TPP Group Seminar History
Date |
Room |
Speaker |
Title |
Dec 12 2024
17:00 |
TBD
|
Cihan Pazarbasi
(Okinawa Institute of Science and Technology)
|
TBA |
ABSTRACT: TBA |
Dec 11 2024
14:00 |
|
Markus Dierigl
(CERN)
|
The Axion is Going Dark |
ABSTRACT: In this talk I will present recent results on bounds on the axion-photon coupling originating from their topological coupling to the gauge sectors of the model (arXiv:2409.02180). These bounds are sensitive to the global structure of the gauge group, i.e., the fate of its 1-form symmetries. In particular I will show that bounds obtained from the Standard Model alone can be reduced significantly if there is a non-Abelian dark sector gauge group that mixes topologically with the visible sector (by gauging of a mutual electric 1-form symmetry). I will further discuss the rich symmetry structure of these generalized axion setups, their phenomenological implications, and generalization of similar constraints in higher dimensions. |
Nov 29 2024
14:00 |
TBD
|
Nicolas Cresto
(Perimeter Institute)
|
Asymptotic Higher Spin Symmetries in Gravity. |
ABSTRACT: I will first give an introductory review of the concepts of Asymptotically Flat Spacetimes, IR triangle and Noether's theorems. I will then present what Asymptotic Higher Spin Symmetries are and how they were introduced as a candidate for an approximate symmetry of General Relativity and the S-matrix. Next, I'll move on to the recent developments of establishing these symmetries as Noether symmetries and describing how they are canonically and non-linearly realized on the asymptotic gravitational phase space. If time permits, I will discuss how the introduction of dual EOM encapsulates the non-perturbativity of the analysis. Based on 2409.12178 and 2410.15219 |
Nov 27 2024
14:00 |
137
|
Zhenghao Zhong
(Oxford)
|
A Radioactive Higgs Mechanism |
ABSTRACT: The Higgs mechanism is a well known process in quantum field theory where scalar fields gain VEVs and gauge groups are broken to subgroups. The same can be done in supersymmetric theories. Today, I will talk about the Higgs mechanism in superconformal field theories (SCFTs) with eight supercharges. Due to a lack of Lagrangian description in much of the SCFTs in the literature, Higgsing is not easy. Using magnetic quivers, we introduce a new algorithm called Decay and Fission which performs Higgs mechanism for SCFTs regardless whether it has a Lagrangian description. I will demonstrate this with many examples in spacetime dimensions d=4,5,6. Finally, I will use the algorithm to arrive at a bound on the landscape of 3d mirror pairs that have quiver gauge theory descriptions. |
Nov 20 2024
14:00 |
Room 137
|
Stathis Vitouladitis
(Universite Libre de Bruxelles)
|
TBA |
ABSTRACT: |
Nov 06 2024
14:00 |
137 (TBC)
|
Josef Seitz
(Weizmann Inst)
|
TBA |
ABSTRACT: TBA |
Oct 30 2024
14:00 |
|
Gabriele Rigo
(Saclay IPhT)
|
A Multiverse Outside of the Swampland |
ABSTRACT: A Multiverse can arise from landscapes without de Sitter minima. It can be populated during a period of eternal inflation without trans-Planckian field excursions and without flat potentials. This Multiverse can explain the values of the cosmological constant and of the weak scale. In the process of proving these statements I derive a few simple, but counter-intuitive results. I show that it is easy to write models of eternal inflation compatible with the distance and refined de Sitter conjectures. Secondly, tunneling transitions that move fields from a lower-energy vacuum to a higher-energy vacuum and generate baby Universes are possible, and occur during eternal inflation. Finally, I relax the assumption of no de Sitter minima and show that this more standard Multiverse can be populated by Coleman-De Luccia transitions in about 100 e-folds of inflation. |
Oct 23 2024
14:00 |
SISSA Room 137
|
Shani Meynet
(Uppsala University)
|
TBA |
ABSTRACT: TBA |
Oct 09 2024
14:00 |
Room 137 (TBD)
|
René Meyer
(University of Wurzburg)
|
|
ABSTRACT: |
Sep 18 2024
14:00 |
Room 137
|
Gaston Giribet
(New York University)
|
TBA |
ABSTRACT: |
Jul 22 2024
14:00 |
room 137, SISSA
|
Yasaman Farzan
()
|
Jovian Signal at BOREXINO |
ABSTRACT: The BOREXINO experiment has been collecting solar neutrino data since 2007, providing the opportunity to study the variation of the event rate over a decade. At 96 % C.L., the rate of low energy events shows a time modulation favoring a correlation with a flux from Jupiter. I will present a new physics model based on dark matter of mass 1-4 GeV captured by Jupiter that can account for such modulation. We discuss how this scenario can be tested. |
Jul 03 2024
14:00 |
137
|
Jacopo Papalini
(University of Ghent)
|
Gravity hologram of double-scaled SYK |
ABSTRACT: In this talk, I will propose the bulk gravitational dual of double scaled SYK. Remarkably, the low energy dynamics of SYK model are captured by the Schwarzian quantum mechanics, which is holographically dual to JT gravity on the disk level. This duality has taught us various lessons about quantum black holes in recent years. Consequently, the bulk dual of DSSYK would provide an all-energy version of JT gravity, potentially offering a version of UV completeness for a theory of quantum gravity. After briefly introducing the SYK model in the double-scaling limit and taking inspiration from the semiclassical analysis, I will construct the relevant holographic dictionary and perform a canonical quantization of the bulk theory, exactly reproducing all amplitudes of DSSYK. The proposed bulk dual will display several fascinating features, such as a deviation of the entropy profile from the usual Hawking formula and the discretization of spacetime at the quantum level. |
Jun 26 2024
14:00 |
Room 137
|
Beatrix Muehlmann
(McGill University)
|
Remarks on 2d quantum cosmology |
ABSTRACT: I will discuss two-dimensional quantum gravity endowed with a positive cosmological constant and coupled to a conformal field theory of large and positive central charge and study cosmological properties at the classical and quantum level. The ADM analysis of the classical phase space, reveals a family of either bouncing or big bang/crunch type cosmologies. At the quantum level, we solve the Wheeler-DeWitt equation exactly identifying wavefunctionals of the Hartle-Hawking and Vilenkin type. We finally retrieve the Hartle-Hawking wavefunction from the disk path integral of timelike Liouville theory. |
Jun 05 2024
14:00 |
Room 137
|
Javi Serra
(Madrid, IFT)
|
Light Scalars Beyond the SM at Finite Density |
ABSTRACT: I will review some of the latest developments in the field of light, weakly-coupled physics beyond the Standard Model at finite density. After introducing the main motivations and presenting the necessary basic concepts of finite density field theory, I will discuss the QCD axion in supernovae, lighter QCD axions in white dwarfs, light QCD-coupled scalars in neutron stars, and relaxion phase transitions seeded by stars. I will conclude by speculating on the potential role of dark compact objects in the vacuum energy of our universe. |
May 29 2024
14:00 |
|
Felix Haehl
(University of Southampton)
|
Euclidean wormholes from arithmetic and quantum chaos |
ABSTRACT: I will discuss two-dimensional CFTs that exhibit a hallmark feature of quantum chaos: universal repulsion of energy levels as described by a regime of linear growth of the spectral form factor. This physical input together with modular invariance strongly constrains the spectral correlations and the subleading corrections to the linear growth. These are determined by a trace formula, which highlights an interplay of universal physical properties of chaotic CFTs and analytic number theory. The trace formula manifests the fact that the simplest possible CFT correlations consistent with quantum chaos are those described by a Euclidean wormhole in AdS3 gravity with [torus]×[interval] topology. While the trace formula immediately provides these results, I will also discuss its mechanism in more detail; in particular, it is interesting to see how a decomposition of the spectral form factor into a set of modular invariant Maass cusp forms encodes quantum chaos. I will end with some perspectives on work in progress regarding the very late time behavior of the spectral form factor (“plateau”). |
May 22 2024
14:00 |
Room 137
|
Diego Redigolo
(INFN Florence)
|
Is Dark Matter Electroweak? |
ABSTRACT: I will present a complete classification of dark matter candidates in a single representation of the EW gauge group and then ask if and how we will be able to discover/exclude this possibility within our lifetimes. |
May 15 2024
14:00 |
Room 135
|
Ethan Torres
(CERN)
|
Giving a KO to 8D Gauge Anomalies |
ABSTRACT: As first pointed out by Garcia-Etxebarria et al, the system of k D7-branes probing an O7^+-plane suffers from a gauge anomaly when k>1. These authors then conjectured that one must couple this theory to an 8D topological field theory (TFT) such that the total system is anomaly-free, thus acting as a ``topological" Green-Schwarz mechanism. In this talk, we will see how to construct such an 8D TFT and show that it indeed cancels the gauge anomaly. The key step will be to engineer the topological operators from D3 branes and fluxbranes placed infinitely far away from the 7-branes. A noteworthy feature of this TFT is that it contains topological operators with vector bundles on their worldvolumes. |
May 06 2024
16:00 |
SISSA
|
Marcos Mariño
(University of Geneva)
|
Trans-series from condensates |
ABSTRACT: The SVZ sum rules were invented as an analytic approach to non-perturbative
quantum field theory (QFT) and have played a crucial role in QCD phenomenology. They combine
the operator product expansion with the assumption of vacuum condensates, and they
can be used to compute exponentially small corrections to perturbative series in QFT. In the language
of the theory of resurgence, they provide a conjectural method to calculate trans-series in QFT.
If the SVZ approach captures fundamental non-perturbative physics,
it should be able to reproduce trans-series which can be obtained from well-established non-perturbative methods.
In this talk I will provide a general overview of the SVZ approach for the theoretician, and then I will present a precision test
of this approach in the Gross-Neveu model, where exact trans-series can be obtained from large N methods.
I will show that the SVZ method correctly reproduces the first two non-perturbative corrections to the fermion self-energy,
as due to a two-quark and a four-quark condensate, and at all loops. |
May 02 2024
14:00 |
137
|
Sunjin Choi
(KIAS)
|
Black hole states at finite N |
ABSTRACT: We study new cohomologies for the local BPS operators of the maximal super-Yang-Mills theory with SU(2), SU(3), and SU(4) gauge groups to better understand the black hole microstates. We first analyze the index of these black hole operators and explicitly construct their cohomologies to study how they imitate the quantum black holes. We find many towers of states and partial no-hair behaviors where certain gravtions are forbidden to dress these black hole operators. This qualitatively agrees with the behavior of the perturbative hairy BPS black holes. Throughout this talk, we mainly focus on a subsector of the field theory corresponding to the BMN matrix theory, which exhibits a black hole like entropy growth at large N. |
Apr 24 2024
11:00 |
139
|
Clara Murgui
(IFAE, Barcelona)
|
Quantum sensors as particle detectors |
ABSTRACT: In this talk, I will present detection techniques for elusive particles based on quantum mechanical properties that evade the typical lower bounds in energy depositions that traditional direct detection experiments can sense. The first part of the talk will focus on decoherence effects on a system of multiple atom quantum states (e.g. two-mode atom interferometer) caused by soft-scatterings with the environment. We will discuss its applicability to light dark matter searches. The second part of the talk will be devoted to searching for dark matter axions by using quantum optomechanics. |
Apr 17 2024
14:00 |
|
Jan Boruch
(Warsaw University)
|
|
ABSTRACT: |
Apr 03 2024
14:30 |
|
TBA
()
|
Joint ICTP/SISSA/UNITS string seminar |
ABSTRACT: |
Mar 27 2024
14:00 |
Room 137
|
Simone Blasi
(Desy)
|
The role of impurities in cosmological phase transitions |
ABSTRACT: Topological defects can play an important role in cosmology. In this talk I will discuss a less explored effect that arises in the context of first order phase transitions, by which defects can act as local impurities catalysing the decay of the false vacuum. This dynamics takes place in one of the simplest extensions of the Standard Model, the xSM, where domain wall configurations associated to the new singlet scalar are shown to enhance the tunneling rate. This dramatically changes the way the electroweak phase transition proceeds, with implications for the corresponding spectrum of gravitational waves. I will finally discuss a similar mechanism involving QCD axion strings at the time of the electroweak phase transition. |
Mar 19 2024
14:00 |
137 SISSA
|
Sean Colin-Ellerin
(UC Berkeley)
|
Graviton entanglement |
ABSTRACT: In recent years, major progress has been made in understanding the connection between quantum information and black hole physics. One of the triumphs has been a calculation of the Page curve for an evaporating black hole from the generalized entropy. However, these results treat the gravitational field as a classical background while they treat the matter as quantum fields. To go beyond this limitation, one must understand the entanglement of gravitons. I will describe work in progress with Andreas Blommaert which elucidates the entanglement properties of gravitons. First, I will provide a Euclidean calculation of graviton entanglement entropy in d-dimensional Rindler spacetime, which receives contributions from d-2 modes living on the entangling surface. Then I will argue that one can interpret these new modes as edge modes coming from the non-factorization of the graviton Hilbert space due to diffeomorphism constraints. These edge modes are surface charges which generate diffeomorphisms of the entangling surface. |
Mar 13 2024
14:00 |
137 SISSA
|
Tatsuhiro Misumi
(Kindai University)
|
More on resurgence in quantum theory |
ABSTRACT: We investigate the resurgent structure of quantum theory, with emphasis on IR-renormalon, phase transition and quantization condition.
(1)We first study the 2D sigma models at large N. We show that the renormalon imaginary ambiguity is cancelled by the combined imaginary ambiguities at the different orders of the trans- series.
(2)We secondly discuss the nontrivial relation between phase transition and Borel singularities. We show the order of phase transition in some QFT can be understood by studying the details of collision of Borel singularities.
(3)We thirdly discuss the application of Exact-WKB to a variety of quantum-mechanical systems. In particular, a generic quantization condition for QM describing a particle on S1 is derived by use of Exact-WKB. |
Mar 06 2024
14:00 |
137
|
Paolo Gregori
(IPhT - CEA Paris-Saclay)
|
Non-perturbative Topological Recursion in Jackiw-Teitelboim Gravity |
ABSTRACT: The connection between matrix models and two-dimensional gravitational theories (including JT gravity) is a very well-established one. For this reason, Topological Recursion has proved to be an invaluable tool for computing observables perturbatively in such theories. In this talk, I will introduce a non-perturbative generalization of Topological Recursion which is particularly well-suited for the study of instanton effects (more specifically, of the ZZ brane type), and apply it to the case of JT gravity. Moreover, by making use of resurgent large order relations, I will show how our results lead to large genus asymptotics of Weil-Petersson volumes. |
Feb 07 2024
14:30 |
TBA
|
TBA
()
|
Joint ICTP/SISSA/UNITS string seminar |
ABSTRACT: |
Feb 06 2024
14:30 |
Room 137 - SISSA Building
|
Saso Grozdanov
(U. Edinburgh, Higgs Ctr. Theor. Phys. and Ljubljana U.)
|
This seminar has been CANCELLED |
ABSTRACT: |
Jan 31 2024
14:00 |
137
|
Giorgos Eleftheriou
(King's College London)
|
The giant graviton expansion in the bulk |
ABSTRACT: We consider four-dimensional N=4 U(N) super Yang-Mills on S^3. The giant graviton expansion is a formula for superconformal indices in such a gauge theory (and others), as a q-series with successive terms suppressed by q^N. The name is due to O(N) being the characteristic scale of wrapped D-branes in the dual theory on AdS_5 x S^5, i.e. giant gravitons. In this talk, I will discuss this expansion for the index of 1/2-BPS states of the theory. I will derive a holographic bulk interpretation of this series by evaluating the corresponding functional integral in the dual. The integral localizes to a product of small fluctuations of the vacuum and of the collective modes of an arbitrary number of giant-gravitons wrapping an S^3 of maximal size inside the S^5. The quantum mechanics of the small fluctuations of one maximal giant is described by a supersymmetric version of the Landau problem. The quadratic fluctuation determinant reduces to a sum over the supersymmetric ground states, and precisely reproduces the first non-trivial term in the infinite series. Further, the terms corresponding to multiple giants are obtained precisely by the matrix versions of the above super-quantum-mechanics. |
Jan 24 2024
16:30 |
137
|
Gabriele di Ubaldo
(IPhT)
|
AdS3/RMT2 Duality |
ABSTRACT: We introduce a framework for quantifying random matrix behavior of 2d CFTs and AdS_3 quantum gravity that is manifestly compatible with conformal and modular invariance. We explain what it means to isolate the chaotic part of the Virasoro primary spectrum of a given theory. This leads to a 2d CFT trace formula, analogous to the Gutzwiller trace formula for chaotic quantum systems, which allows us to identify conditions for random matrix universality in 2d CFT. We use this to understand the off-shell Cotler-Jensen torus wormhole of AdS_3 pure gravity from a purely microscopic CFT point of view. This wormhole is shown to be extremal, a minimal completion of the random matrix theory two-point correlator compatible with the symmetries. By factorizing this wormhole, we determine a new piece of the AdS_3 pure gravity path integral with a single torus boundary; this contains fine-grained spectral data of the black hole microstates of pure gravity. |
Jan 10 2024
14:00 |
Room 137
|
Tin Sulejmanpasic
(Durham University)
|
The phases of theories with the Z_N 1-form symmetry |
ABSTRACT: Theories with discrete 1-form symmetries, which feature SU(N) gauge theories and Z_N lattice gauge theories are discussed. By adequately perturbing the theory in which the symmetry is spontaneously broken (the TQFT phase), I will argue that generically there is one phase in 2d (confined), two phases in 3d (confined and TQFT) and 3 phases in 4d (confined, TQFT and coulomb/photon phase). I will show explicitly how these arise in Z_N lattice gauge theory. The analysis will reveal some surprising insight into confinement and the role of monopoles and so-called center vortices, the two mechanisms of confinement which are discussed in the literature since the 70s. |
Dec 15 2023
10:00 |
old SISSA building, Aula D
|
TBA
(TBA)
|
Trilateral phenomenology meeting (Trieste-Ljubljana-Nova Gorica) |
ABSTRACT: |
Dec 13 2023
14:00 |
Room 005
|
Ville Vaskonen
(Padua U., NICPB, Tallinn)
|
Slow and supercooled cosmological phase transitions |
ABSTRACT: The Universe may have deviated from the radiation-dominated expansion during the earliest epochs. Processes causing that can have interesting observable consequences. In this talk, I will focus on strongly supercooled phase transitions that cause a secondary period of exponential expansion of the Universe. I will describe a class of particle physics models where such transitions can happen and discuss the observable consequences of the process in the form of gravitational waves (GWs) and primordial black holes (PBHs). I will show that if the transition is slow the GW signal generated by colliding bubble walls and fluid shells can be very strong and potentially gives a good fit to the GW background recently discovered in the pulsar timing array data. I will also show that such slow transitions lead to the formation of a large PBH abundance that can constitute all dark matter and a secondary GW signal that dominates over the signal formed by the bubble walls and fluid shells if the transition is sufficiently slow. |
Dec 07 2023
16:00 |
Room 131 SISSA
|
Denis Karateev
(University of Geneva)
|
Trace anomalies and the dilation-graviton amplitude |
ABSTRACT: We consider 3+1 dimensional Quantum Field Theories (QFTs) coupled to the dilaton and the graviton. We show that the graviton-dilaton scattering amplitude receives a universal contribution which is helicity flipping and is proportional to (∆c − ∆a) along any RG flow, where ∆c and ∆a are the differences of the UV and IR c- and a-trace anomalies respectively. This allows us to relate (∆c − ∆a) to spinning massive states in the spectrum of the QFT. We test our predictions on a simple example of a massive free scalar. We discuss possible applications. |
Nov 30 2023
14:00 |
|
Guido Martinelli
(La Sapienza)
|
Flavor physics, the Unitarity Fit, Anomalies and all that |
ABSTRACT: |
Nov 22 2023
14:00 |
|
Álvaro Pastor Gutiérrez
(Heidelberg, Max Planck)
|
Unveiling hidden phases and charting strong sectors |
ABSTRACT: While the Standard Model of particle physics has been extremely successful in predicting experimental results, it still leaves us with unanswered questions about dark matter, the imbalance between matter and antimatter, and the emergence of fundamental scales. In this presentation, I will outline our initial efforts to explore strong new physics scenarios using the non-perturbative functional renormalisation group. I will begin by introducing the flow equation and applying it to the Standard Model, thereby uncovering previously uncharted high-energy phases in the Higgs potential. The second part of the talk will focus on a comprehensive study of (quasi-)conformal “Technicolour” theories, aiming to identify Higgs-like bound states and detectable dark sectors. To achieve this, we will employ bosonisation techniques, which provide valuable insights into the properties of dynamically emergent bound states. I will conclude with a specific case study addressing the flavour puzzle within the framework of fundamental partial compositeness. |
Nov 15 2023
14:00 |
TBA
|
Beatrix Mühlmann
(McGill U.)
|
The Virasoro Minimal String |
ABSTRACT: I will introduce a critical string theory in two dimensions and explain that this theory, viewed as two-dimensional quantum gravity on the worldsheet, admits an equivalent holographic description in terms of a double-scaled matrix integral. The worldsheet theory consists of Liouville CFT with central charge c>25 coupled to timelike Liouville CFT with central charge 26-c. The dual matrix integral has as its leading density of eigenvalues the universal Cardy density of primary states in a two-dimensional CFT of central charge c, which motivates the name of the theory. This duality holds for any value of the continuous parameter c and reduces to the well-known JT gravity/matrix integral duality in the large central charge limit, thus providing a precise stringy realization of JT gravity. This talk is based on work with Scott Collier, Lorenz Eberhardt, and Victor Rodriguez. |
Oct 25 2023
14:00 |
137
|
Arsenii Titov
(University of Pisa)
|
Modular invariance and the strong CP problem |
ABSTRACT: TBA |
Oct 20 2023
14:30 |
TBA
|
Vineeth Krishna Talasila
(Tata Institute of Fundamental Research, Mumbai)
|
TBA |
ABSTRACT: TBA |
Oct 11 2023
14:00 |
TBA
|
Michele Galli
(Humboldt U., Berlin)
|
TBA |
ABSTRACT: TBA |
Sep 18 2023
14:00 |
room 137
|
Neil Barrie
(University of Sidney)
|
Type II Seesaw Leptogenesis |
ABSTRACT: The Type II Seesaw Mechanism provides a minimal framework to explain the neutrino masses involving the introduction of a single triplet Higgs to the Standard Model. However, this simple extension was believed to be unable to successfully explain the observed baryon asymmetry of the universe through Leptogenesis. We have demonstrated that the triplet Higgs of the Type II Seesaw Mechanism alone can simultaneously generate the observed baryon asymmetry of the universe and the neutrino masses while playing a role in setting up Inflation. This is achievable with a triplet Higgs mass as low as 800 GeV, and predicts that the neutral component obtains a small vacuum expectation value v_∆< 10 keV. I will discuss the rich phenomenology of our model which can be tested by various terrestrial experiments as well as by astronomical observations. In particular, the successful parameter region may be probed at a future 100 TeV collider, upcoming lepton flavor violation experiments such as Mu3e, and neutrinoless double beta decay experiments.rnBased on: 2106.03381, 2204.08202, 2210.02110 |
Sep 13 2023
14:00 |
Room 137
|
Valdo Tatitscheff
(Heidelberg University)
|
One-form symmetries in N=3 S-folds |
ABSTRACT: I will review the classification of global one-form symmetries in the non-Lagrangian N = 3 SCFTs that are worldvolume theories of type IIB D3-branes on S-fold 3-planes. In such a brane setup, (p,q)-strings naturally represent massive dynamical states of the low-energy effective theory on the Coulomb branch. From the knowledge of the massive spectrum, one can in turn compute the one-form symmetries by listing all maximal collections of mutually-local genuine line operators; these results point towards the existence of non-invertible symmetries for some of these N = 3 SCFTs. |
Sep 06 2023
14:00 |
room 137
|
Claudia Hagedorn
(Valencia IFIC)
|
Flavour anomalies meet flavour symmetry |
ABSTRACT: We propose an extension of the Standard Model with a leptoquark and a flavour symmetry that is the direct product of a dihedral and a cyclic group. We show that both the flavour anomalies in R(D) and R(D*) and of the anomalous magnetic moment of the muon as well as the charged fermion mass hierarchy and the quark mixing pattern can be explained. At the same time, constraints imposed from e.g. the non-observation of charged lepton flavour violating processes can be passed in this model for masses of the leptoquark as small as 2 TeV. The flavour structure of the couplings between the leptoquark and the Standard Model fermions is determined by a residual group of the flavour symmetry. Only four spurions, acquiring different vacuum expectation values, are necessary in order to achieve the desired form of the leptoquark couplings and of the charged fermion mass matrices. We study the phenomenology of this model with analytic estimates as well as perform numerical scans of its parameter space. |
Jul 05 2023
0:00 |
SISSA
|
Simone Rota
(UniMi, Milan)
|
1-form symmetries in N=3 S-fold SCFTs |
ABSTRACT: I will discuss the classification of 1-form symmetries in N=3\r\nfour dimentional SCFTs engineered in Type IIB in presence of an S-fold. The charge lattice of the theories is obtained by analyzing (p,q)-strings on the S-fold background. Then the line operators are determined via field-theoretical techniques, that I will explain. The 1-form symmetries and the possible global structures are determined for all N=3 S-fold SCFTs, and checked against recent results in the literature. I will then discuss the construction of non-invertible symmetry defects in some N=3 S-fold SCFTs. |
Jun 28 2023
14:00 |
SISSA
|
Ohad Mamroud
(Weizmann Inst.)
|
TBA |
ABSTRACT: TBA |
Jun 21 2023
14:00 |
SISSA
|
Giovanni Rizi
(SiSSA)
|
TBA |
ABSTRACT: TBA |
May 31 2023
14:00 |
SISSA room 137
|
Victor Godet
(Tata Inst.)
|
The Hilbert space of de Sitter quantum gravity |
ABSTRACT: I will describe how the Wheeler-DeWitt equation can be solved in the late-time expansion of an asymptotically de Sitter spacetime. The physical states are found to be wavefunctionals with the same symmetries as CFT partition functions, so that the Hilbert space is "theory space". The inner product can be defined using a suitable procedure to gauge-fix the Weyl and diffeomorphism invariance and the residual conformal symmetry imposes dS invariance. I will discuss how cosmological correlators can be interpreted as gauge-fixed observables and satisfy a cosmological version of the holography of information. |
May 24 2023
14:00 |
|
Hector Gisbert
(U. Padova)
|
Flavorful tests of the SM symmetries |
ABSTRACT: Flavor physics has been instrumental in developing the Standard Model (SM). In this talk, I will exploit the exact (or softly broken) symmetries of the SM to construct sensitive observables for the search for new physics in up and down sectors. By leveraging the correlations and complementarity between different systems, we will construct tests of the SM symmetries, highlighting their implications for the construction of a more complete theory. |
May 10 2023
14:00 |
|
Richard Ruiz
(Cracow, INP)
|
Life at a Multi-TeV Muon Collider |
ABSTRACT: In this talk we present a picture of what life is like at a multi-TeV
muon collider. We start by showing that beyond a few TeV electroweak
(EW) boson fusion/scattering becomes the dominant roduction vehicle at
lepton colliders for both the Standard Model and new physics.
Motivated by this, we revisit the treatment of weak gauge bosons as
constituents of high-energy leptons. In particular, using a new,
public implementation of (polarized) W/Z parton distribution functions
in the Monte Carlo event generator MadGraph5_aMC@NLO, we report the
size of universal, i.e., process independent, corrections that spoil
the accuracy of a (factorized) scattering formula for muon colliders.
Guided by this insight, we give an outlook for polarized EW boson
scattering at many TeVs. |
Apr 26 2023
14:00 |
|
Majid Ekhterachian
(EPFL Lausanne)
|
Conformal leptogenesis and cosmological phase transition of composite Higgs confinement |
ABSTRACT: I will discuss the cosmological confining phase transition (PT) of nearly conformal, strongly coupled large N field theories, applicable to composite Higgs models, using their holographic dual 5D formulation. In this description, the PT is from the high temperature phase in which the IR of the warped extra dimension is covered by a black-brane horizon to the low temperature Randall-Sundrum-1 phase. The PT proceeds by percolation of IR-brane bubbles nucleating from the horizon, and the bubble dynamics during the PT sources a stochastic gravitational wave background that can be detected by future experiments. I will show how to construct a smooth “bounce” configuration that allows for a controlled description of bubble nucleation within 5D EFT. The cosmological PT in the minimal models can complete only after a large period of supercooling, potentially resulting in excessive dilution of primordial matter abundances. However, generic modification of the minimal models can result in a much faster completion of the PT, allowing for the possibility of baryogenesis before the PT. I will then discuss baryogenesis via leptogenesis in these models, where the asymmetry is generated by out of equilibrium decays of elementary Majorana Fermions into the CFT (unparticle) states. This mechanism, implemented in composite Higgs models, features an interesting interplay between the asymmetry generation at the high scale and the dilution and washout at the confinement scale to reproduce the observed baryon asymmetry. |
Apr 19 2023
14:00 |
SISSA room 137
|
hep-th: Aldo Cotrone
(INFN, Florence and Florence U.)
|
Vintage Holography, Fashion Pheno? |
ABSTRACT: After recalling some basic features of the Sakai-Sugimoto model of Holographic QCD, I will describe in some details a global string in its deconfining phase. In the confining phase, the string bounds "domain walls", whose properties can be derived for simple configurations. Finally, I will discuss the possibility of charging the strings and potential phenomenological applications. |
Mar 29 2023
15:00 |
SISSA: room 128-129
|
hep-th: Atul Sharma
(Harvard)
|
Top-down holography in an asymptotically flat spacetime |
ABSTRACT: I will describe a top-down construction of a toy example of celestial holography, based on recent work with K. Costello and N. M. Paquette. Our duality relates certain models of self-dual gauge and gravitational theories, placed on an asymptotically flat 4d spacetime called Burns space, to a 2d chiral algebra describing the worldvolume dynamics of D1-branes in a topological string theory. Time permitting, I will conclude by discussing simple tests of the duality matching amplitudes in the bulk with correlators in the dual. |
Mar 15 2023
14:00 |
SISSA room 128-129
|
hep-th: Manus Visser
(Cambridge U., DAMTP)
|
Partition function for a volume of space |
ABSTRACT: In their seminal 1977 paper, Gibbons and Hawking applied concepts of quantum statistical mechanics to ensembles containing black holes, finding that a semiclassical saddle point approximation to the partition function recovers the laws of black hole thermodynamics. I will generalise the Gibbons-Hawking method by defining a partition function of a ball of space at fixed proper volume. In the zero-loop approximation the result is the exponential of the Bekenstein-Hawking entropy of the boundary of the ball, indicating the holographic nature of nonperturbative quantum gravity in generic finite volumes of space. This talk is based on the recent work 2212.10607 with Ted Jacobson. |
Feb 22 2023
14:00 |
|
Luca Di Luzio
(U. Padova)
|
Rethinking the QCD axion |
ABSTRACT: Four decades after its prediction the axion remains the most compelling solution to the strong CP problem and a well-motivated dark matter candidate, inspiring several ultrasensitive experiments based on axion-photon mixing. After reviewing the axion solution to the strong CP problem, I will focus on recent developments in axion model building suggesting that the QCD axion parameter space is much larger than what traditionally thought. Implications for astrophysical limits and future experiments will be discussed as well. |
Feb 15 2023
14:00 |
SISSA room 128-129
|
hep-th: Matteo Sacchi
(Oxford University)
|
Mixed anomalies and generalized symmetries from 3d superconformal indices |
ABSTRACT: Generalized symmetries and their mixed anomalies have proved to be useful in providing non-trivial constraints on the dynamics of QFTs. A natural question is whether these are related in any way to supersymmetric partition functions or indices, which have also been used extensively to study SQFTs. In this talk, we address this question in the context of 3d $mathcal{N} geq ≥3$ gauge theories using the superconformal index. In particular, using the index we are able to detect mixed anomalies involving discrete 0-form symmetries, and possibly a 1-form symmetry. Gauging appropriate symmetries involved in such mixed anomalies, we obtain various interesting theories with two-group structures or non-invertible symmetries. |
Feb 08 2023
14:00 |
SISSA: room 128-129
|
hep-th: Seok Kim
(Seoul Natl. U.)
|
A black hole cohomology problem in AdS/CFT |
ABSTRACT: I will explain a classical cohomology problem for the local
BPS operators in N=4 super-Yang-Mills theory and how this is related
to the microstates of BPS black holes in AdS. I will also explain some
recent progress on this problem. |
Dec 14 2022
14:00 |
SISSA 136
|
hep-th: Jingxiang Wu
(Oxford University)
|
Holomorphic Twist and Confinement |
ABSTRACT: I will describe a procedure, known as holomorphic twist, to isolate protected quantities in supersymmetric quantum field theories.
The resulting theories are holomorphic, interacting and have infinite dimensional symmetries, analogous to the holomorphic half of a 2D CFT.
I will explain how to study quantum corrections to these symmetries and other higher operations. As a surprise, we find a novel UV
manifestation of confinement, dubbed as "holomorphic confinement," in the example of pure SU(N) super Yang-Mills. |
Dec 14 2022
15:30 |
SISSA
|
hep-th: Guillermo Arias-Tamargo
(ICTEA, Oviedo and Oviedo U.)
|
Non-invertible symmetries from discrete gauging |
ABSTRACT: In this talk, I will discuss 1-form symmetries and (d-2)-form symmetries of gauge theories based on disconnected gauge groups which include charge conjugation. For pure gauge theories, the 1-form symmetries are shown to be non-invertible. I will also discuss constructions of theories with these gauge groups in String Theory. |
Dec 06 2022
14:00 |
Bubbletrons
|
Filippo Sala
(University of Bologna)
|
|
ABSTRACT: |
Dec 05 2022
14:00 |
|
Julius Grimminger
(Imperial Coll., London)
|
TBA |
ABSTRACT: TBA |
Nov 30 2022
14:00 |
Online
|
hep-th: Giuseppe Dibitetto
(Rome University)
|
Stringy multifield quintessence and the Swampland |
ABSTRACT: We consider quintessence models within 4D effective
descriptions of gravity coupled to two scalar fields. These theories are known to give rise to viable models of late-time cosmic acceleration without any need for flat potentials, and so they are potentially in agreement with the dS Swampland onjecture. In this paper we investigate the possibility of consistently embedding such constructions in string theory. We identify situations where the quintessence fields are either closed string universal moduli or non-universal moduli such as blow-up modes. We generically show that no trajectories compatible with today’s cosmological parameters exist, if one starts from matter-dominated initial conditions. It is worth
remarking that universal trajectories compatible with observations do appear, provided that the starting point at early times is a phase of kinetic domination. However, justifying this choice of initial conditions on solid grounds is far from easy. We conclude by studying Q-ball formation in this class of models and discuss constraints coming from Q-ball safety in all cases analyzed here. |
Nov 23 2022
16:00 |
SISSA: room 136
|
hep-th: Gianluca Inverso
(Padova University)
|
2d gauged supergravities and Kaluza–Klein consistent truncations |
ABSTRACT: Certain classes of flux compactifications can be described in terms of gauged supergravity theories.
In particular, identifying reductions leading to maximal supergravities can be especially useful for solution generation, precision tests of holography, and tests of some swampland conjectures.
A very interesting case is the study of D=2 models: this is the realm of AdS_2 solutions (and domain walls), with prototype example the AdS_2 x S^8 solution of IIA supergravity dual to the D0 brane matrix model. Reductions to D=2 have however stayed underdeveloped compared to higher dimensions.
In this talk I will introduce the necessary structures to study Kaluza--Klein truncations to D=2 gauged (maximal, super)gravities and complete the (bosonic) formulation of the latter. I will provide a formulation of 2d gravity+dilaton+NLSM theories covariant under their infinite-dimensional symmetries and compatible with non-Abelian T-dualities, and its extension to 11d and IIB supergravity via exceptional field theory. As an example application I will prove the full embedding of SO(9) gauged maximal supergravity into type IIA supergravity on AdS_2 x S^8. |
Nov 23 2022
14:00 |
Lecture hall: 138
|
Claudia Cornella
(Mainz University)
|
Gauge Invariance and Finite Counterterms in Chiral Gauge Theories |
ABSTRACT: |
Nov 16 2022
15:00 |
SISSA aula 004
|
hep-th: Fridrik Freyr Gautason
(University of Iceland)
|
Wilson loops and non-conformal Holography |
ABSTRACT: I will discuss two examples of non-conformal holographic theories. First is the maximally supersymmetric Yang-Mills theory in five dimensions, and the second is a mass deformation of N=4 SYM in four dimensions commonly known as N=2^*. Using supersymmetric localization, the expectation value of BPS Wilson loop operator can be computed exactly at large rank and strong coupling in both of these theories. In the talk I will review these results and explain how to reproduce them in string theory. |
Nov 09 2022
14:00 |
|
Anish Ghoshal
(Warsaw U.)
|
CANCELLED |
ABSTRACT: |
Oct 26 2022
14:00 |
|
Elisa Todarello
(Turin U.)
|
Axion miniclusters and their survival in the galaxy |
ABSTRACT: |
Oct 19 2022
15:00 |
Aula 134
|
hep-th: Jeremias Aguilera Damia
(ULB)
|
Non invertible symmetry defects in five dimensions |
ABSTRACT: In the last few years, an increasing effort has been put towards the characterization of global symmetries in Quantum Field Theory in several dimensions. Along the way, some novel notions of symmetry, such as higher form symmetries and non-invertible symmetries, have been uncovered and, moreover, shown to arise in a large variety of physical systems. After briefly reviewing some of these novel notions of symmetry, we will describe a minimalistic setup featuring both higher form and non-invertible symmetries, namely Chern Simons theory in five dimensions. We will also briefly mention some simple connections with lower dimensional constructions and holography. |
Oct 05 2022
15:00 |
Zoom
|
Matthew Heydeman
(IAS)
|
Near BPS black holes in AdS5 and N=4 SYM |
ABSTRACT: It is an open problem to understand the ultimate fate of the path integral in gravity and quantum black hole thermodynamics. Recent progress has focused on supersymmetric black holes in asymptotically AdS spacetimes in which the sum over classical BPS solutions reproduces the superconformal index of the dual CFT. In a parallel line of development, it has been understood that certain models of 2d gravity describe the near horizon region of a near-extremal black hole. At strong coupling the integral over metrics in these models may be done exactly, and the solution reveals a coarse-grained chaotic spectrum with no sharply defined microstates.
In this talk, we will show that these two approaches are compatible and compute the low-temperature partition function of near-BPS black holes via a gravitational path integral. We will focus on these low temperature corrections around nearly 1/16-BPS black holes in asymptotically AdS5 x S5 space, dual to heavy operators in N=4 SYM. We argue these quantum corrections come from a version of the N=2 super-Schwarzian theory which captures the breaking of the SU(1,1|1) near horizon symmetry at finite temperature and chemical potential. The quantization of this theory gives a quantum gravitational derivation of the extremal entropy and the superconformal index, showing that supergravity at strong coupling may exhibit both exact microstates and a chaotic spectrum. Additionally, we show the presence of a gap between the BPS black holes and the lightest near-BPS black holes, and we will give a prediction for the spectrum of near-BPS states that lie above this gap. Time permitting, we will discuss stringy and non-perturbative corrections that can affect the black hole spectrum, as well as the relationship to boundary models such as SYK. |
Jul 05 2022
15:00 |
SISSA
|
Sougata Ganguly
(Indian Association for the Cultivation of Science)
|
Non-adiabatic evolution of dark sector in the presence of U(1)Lμ−Lτ gauge symmetry |
ABSTRACT: |
Jun 24 2022
14:00 |
137
|
Triparno Bandyopadhyay
(TIFR)
|
Sifting through the SM for the hints of an ALP |
ABSTRACT: Axion-like particles (ALPs) are at the forefront of physics research,
especially at the intensity frontier, dealing with light weakly coupled
particles. A plethora of different experiments search for signals of
the ALP in many different final states using innovative search
strategies. We present a different perspective on ALP searches,
concentrating on the modifications that such a particle causes to the
known Standard Model (SM) results. The presence of a low lying ALP
modifies the SM in non-trivial ways. We systematically derive the
leading order chiral lagrangian in the presence of an ALP (A𝛘PT). Then,
using the derived A𝛘PT, we systematically discuss three distinct
modifications to SM physics---which arise at the tree level itself: i)
those to the meson mass spectrum, ii) those to hadronic form factors,
leading to modified to partial decay rate distributions of the mesons,
and iii) those to the sum rules constructed out of meson decay
amplitudes. As a proof of concept example of our program, we analyse
semi-leptonic Kaon decay data collected by the NA48/2 collaboration to
find bounds on the ALP parameter space. |
Jun 22 2022
14:00 |
|
Ben Stefanek
(University of Zurich)
|
Flavor hierarchies, flavor anomalies, and the Higgs mass from a warped extra dimension |
ABSTRACT: In recent years a series of anomalies hinting at lepton flavor universality violation in B-meson decays have emerged. Interestingly, these anomalies can be coherently explained at the TeV scale by "4321" gauge models with hierarchical couplings reminiscent of the Standard Model (SM) Yukawas. This provides a tantalizing hint of new physics connected to the SM flavor puzzle at the same scale where the electroweak (EW) hierarchy problem is expected to be resolved. I review these models, discuss some new phenomenological implications, and show that they can arise as the low-energy limit of a complete theory of flavor, based on a warped fifth dimension where each SM family is quasi-localized in a different brane. The SM Higgs is identified as a pseudo-Nambu-Goldstone boson emerging from the same dynamics responsible for breaking 4321 gauge symmetry. This novel construction unifies quarks and leptons in a flavor non-universal manner, provides a natural description of flavor hierarchies, and addresses the EW hierarchy problem a la Randall-Sundrum. |
Jun 01 2022
15:00 |
TBA
|
Antonio Antunes
(Porto University)
|
TBA |
ABSTRACT: TBA |
May 18 2022
15:00 |
SISSA
|
Luigi Tizzano
(ULB)
|
TBA |
ABSTRACT: TBA |
May 04 2022
15:00 |
Online
|
Clay Cordova
(Chicago U., EFI)
|
TBA |
ABSTRACT: TBA |
Apr 20 2022
15:00 |
Online
|
Eric Sharpe
(Virginia Tech)
|
TBA |
ABSTRACT: TBA |
Apr 06 2022
15:00 |
TBA
|
Antoine Bourget
(ENS Paris)
|
Singularities in the Moduli Space of Instantons |
ABSTRACT: In this talk I will address the singular structure of the moduli space of instantons in R^4. As this space is singular and hyperKahler, it can be described using a magnetic quiver. The subtleties of the moduli space of instanton requires the introduction of a new kind of quivers, which carry decorations. I will demonstrate the consequences of this new understanding for the classification of SCFTs in various dimensions. |
Mar 23 2022
15:00 |
Online
|
Himanshu Khanchandani
(Princeton University)
|
CFT in AdS and Gross-Neveu BCFT |
ABSTRACT: I will start by describing the general idea of studying CFT in AdS to extract BCFT data from it. After discussing some simple examples, I will apply this idea to $U(N)$ Gross-Neveu (GN) model. I will describe various possible boundary phases of the model in the large $N$ limit in 2 < d < 4 dimensions, as well in an epsilon expansion in $d = 2 + epsilon$ and $d = 4 - epsilon$ dimensions for arbitrary $N$. Based on arXiv: 2007.04955and arXiv: 2110.04268. |
Mar 09 2022
15:00 |
Online
|
Federico Bonetti
(Oxford U., Inst. Math.)
|
TBA |
ABSTRACT: TBA |
Feb 23 2022
15:00 |
Room 138
|
Claudio Coriano
(INFN Lecce)
|
Conformal Symmetry, Amplitudes in Momentum Space and Anomaly Actions |
ABSTRACT: An overview of CFT in d=4 in momentum space and its anomalous conformal Ward identities is presented. We will then discuss the implications of such constraints on the structure of anomaly actions in general gravitational backgrounds. This allows to investigate the conformal back-reaction of a conformal sector on external gravity, and the role played by the topological Gauss-Bonnet (GB) term. A discussion of recent proposals for evading Lovelock's theorem at d=4 in the Einstein Gauss-Bonnet theory is also presented. |
Feb 09 2022
17:00 |
Online
|
Lampros Lamprou
(U. British Columbia)
|
TBA |
ABSTRACT: TBA |
Jan 26 2022
14:00 |
Room 138
|
Pieter Bomans
(University of Padova)
|
One-dimensional sectors from the squashed sphere |
ABSTRACT: In this talk I will show that every three-dimensional N=4 supersymmetric field theory on the squashed sphere contains a set of protected operators whose correlation functions are governed by a one-dimensional theory. This one-dimensional theory arises from supersymmetric localization with respect to a special supercharge which is not contained in any N=2 subalgebra of the supersymmetry algebra. For theories built out of vector and hypermultiplets I will explicitly construct the one-dimensional theory and discuss its most important properties. |
Jan 19 2022
13:30 |
SISSA, Big meeting room on the 7th floor SISSA
|
Guido Martinelli
(Univ. of Rome, "La Sapienza")
|
News from the lattice, Anomalies and the Unitary Triangle Fit |
ABSTRACT: |
Jan 12 2022
15:00 |
Online
|
Joao Melo
(Cambridge U., DAMTP)
|
The Propagator Matrix Reloaded |
ABSTRACT: For quantum fields in curved spacetimes there isn\'t a unique notion of vacuum state and the in and out vacua might be different, therefore, to perform calculations with interacting theories we require the use of the Schwinger-Keldysh formulation, very similar to undergraduate quantum mechanics. However, the usual assumption that the theory is free at past infinity isn\'t necessarily true and there is a need to modify the usual formalism to take this into account, resulting in a 3x3 matrix of propagators instead of the more familiar 2x2. In my talk I will describe this new formalism and test it in flat spacetime with the surprising conclusion that even in Minkowski spacetime it seems like the theory isn\'t free at past infinity at finite temperature as is commonly assumed. |
Dec 15 2021
15:00 |
Zoom
|
Csaba Csaki
(Cornell)
|
TBA |
ABSTRACT: |
Dec 03 2021
14:00 |
|
Quentin Bonnefoy
(DESY)
|
TBA |
ABSTRACT: |
Nov 24 2021
15:00 |
Sissa
|
Gabriele lo Monaco
(IPhT Saclay)
|
TBA |
ABSTRACT: |
Nov 17 2021
14:00 |
|
Ennio Salvioni
(University of Padua)
|
|
ABSTRACT: |
Nov 16 2021
17:00 |
zoom
|
Vedran Brdar
(Fermilab)
|
|
ABSTRACT: |
Nov 15 2021
17:00 |
zoom
|
Davide Racco
(Stanford University)
|
|
ABSTRACT: |
Nov 12 2021
10:00 |
ZOOM
|
Andrea Thamm
(University of Melbourne)
|
|
ABSTRACT: |
Nov 10 2021
15:00 |
|
Adar Sharon
(Weizmann)
|
TBA |
ABSTRACT: |
Nov 09 2021
14:00 |
137
|
Julia Harz
(TUM)
|
|
ABSTRACT: |
Nov 08 2021
14:00 |
137
|
Gauthier Durieux
(CERN)
|
|
ABSTRACT: |
Nov 05 2021
14:00 |
ZOOM
|
Ivan Martinez Soler
(Harvard)
|
|
ABSTRACT: |
Nov 05 2021
15:00 |
Zoom
|
Arash Arabi Ardehali
(YITP, Stony Brook)
|
Cardy-like limits of the 4d superconformal index and AdS/CFT |
ABSTRACT: We will discuss asymptotics of a certain partition function (known as the superconformal index) of the 4d N=4 CFT in various limits, and find infinite series of saddles. From the point of view of the Euclidean path integral of the dual AdS theory, some of the saddles correspond to the bulk black hole and its orbifolds. Other saddles seem to correspond to bulk black lenses and their orbifolds. |
Nov 04 2021
14:00 |
136
|
Admir Greljo
(University of Bern)
|
|
ABSTRACT: |
Oct 21 2021
0:00 |
Zoom
|
Arash Arabi Ardehali
(YITP, Stony Brook)
|
Cardy-like limits of the 4d superconformal index and AdS/CFT |
ABSTRACT: We will discuss asymptotics of a certain partition function (known as the superconformal index) of the 4d N=4 CFT in various limits, and find infinite series of saddles. From the point of view of the Euclidean path integral of the dual AdS theory, some of the saddles correspond to the bulk black hole and its orbifolds. Other saddles seem to correspond to bulk black lenses and their orbifolds. |
Oct 20 2021
15:00 |
Zoom
|
Masataka Watanabe
(Weizmann Institute)
|
Integrability and/or resurgence from EFT |
ABSTRACT: I will talk about how integrability puts constraints on the coefficients of EFT at large chemical potential. |
Oct 06 2021
15:00 |
Zoom
|
Aleix Gimenez Grau
(DESY)
|
Bootstrapping holographic defect correlators in N = 4 super Yang-Mills |
ABSTRACT: We study two-point functions of single-trace half-BPS operators in the presence of a supersymmetric Wilson line in N = 4 SYM. We use inversion formula technology in order to reconstruct the CFT data starting from a single discontinuity of the correlator. In the planar strong coupling limit only a finite number of conformal blocks contributes to the discontinuity, which allows us to obtain elegant closed-form expressions for two-point functions of single-trace operators O_J of weight J = 2,3,4. Our final result passes a number of non-trivial consistency checks: it has the correct discontinuity, it satisfies the superconformal Ward identities, it has a sensible expansion in both defect and bulk OPEs, and is consistent with available results coming from localization. The method is completely algorithmic and can be implemented to calculate correlators of arbitrary weight. |
Jun 16 2021
16:00 |
Zoom
|
Shu-Heng Shao
(IAS Princeton)
|
TBA |
ABSTRACT: |
May 26 2021
14:30 |
Zoom
|
Rodolfo Russo
(QMLU London)
|
The Eikonal Approach to Gravitational Scattering and Radiation |
ABSTRACT: |
May 19 2021
15:30 |
Zoom
|
Irene Valenzuela
(Harvard)
|
TBA |
ABSTRACT: |
May 05 2021
17:00 |
Zoom
|
Gustavo Joaquin Turiaci
(UC Santa Barbara)
|
TBA |
ABSTRACT: |
Apr 21 2021
14:30 |
Zoom
|
Riccardo Rattazzi
(EPFL Lausanne)
|
TBA |
ABSTRACT: |
Apr 14 2021
14:00 |
|
Angelo Esposito
(EPFL, Lausanne)
|
Condensed matter for the particle physicist: phenomenological applications |
ABSTRACT: In this talk I will present the EFT approach to different phases of matter, and its applicability to high energy phenomenology. I will first introduce the conceptual aspects of this approach, with particular emphasis on the role played by spacetime symmetries and their spontaneous breaking. I will then describe two instances where this new viewpoint on condensed matter has proven useful for phenomenology. The first one is the determination of the mass transported by a sound wave, with possible applications ranging from dark matter detection to the determination of background signals in LIGO. The second is the study of the response of a possibile He-4 detector to the passage of a sub-GeV dark matter, which could represent a promising proposal for future dark matter experiments. |
Apr 07 2021
14:30 |
Zoom
|
Kristan Jensen
(University of Victoria)
|
Wormholes and black hole microstates in AdS/CFT |
ABSTRACT: It has long been known that the coarse-grained approximation to the black hole density of states can be computed using classical Euclidean gravity. In this talk I will argue for another entry in the dictionary between Euclidean gravity and black hole physics, namely that Euclidean wormholes describe a coarse-grained approximation to the energy level statistics of black hole microstates. We do so by using the method of constrained instantons to obtain an integral representation of wormhole amplitudes in Einstein gravity and in full-fledged AdS/CFT. These amplitudes are non-perturbative corrections to the two-boundary problem in AdS quantum gravity. The full amplitude is likely UV sensitive, dominated by small wormholes, but it admits an integral transformation with a macroscopic, weakly curved saddle-point approximation. The saddle is the "double cone" geometry of Saad, Shenker, and Stanford, with fixed moduli. In the boundary description this saddle appears to dominate a smeared version of the connected two-point function of the black hole density of states, and suggests level repulsion in the microstate spectrum. I will also discuss the stability of these wormholes to small fluctuations and to brane nucleation. Our results indicate a factorization paradox in AdS/CFT, and I will discuss a potential mechanism for understanding it. |
Mar 24 2021
16:00 |
Zoom
|
Monica Pate
(Harvard)
|
Scattering amplitudes on the celestial sphere |
ABSTRACT: The identification of quantum field theoretic soft theorems with constraints from infinite-dimensional asymptotic symmetries offers exciting prospects for solving the scattering problem in quantum gravity. In four spacetime dimensions, the asymptotic symmetry group includes the local conformal (Virasoro) symmetry of two dimensions, motivating the proposal that 4D scattering is holographically dual to a 2D conformal theory. Lorentz symmetry in four dimensions comprises the global part of the 2D conformal group of the dual. Asymptotic particles in boost as opposed to standard momentum eigenstates transform like primary operators, and thereby manifestly exhibit the underlying conformal symmetry. Scattering amplitudes for such states -- known as celestial amplitudes -- involve contributions from asymptotic particles of arbitrarily high energy and accordingly do not respect the familiar paradigm of Wilsonian IR/UV decoupling. Nevertheless, I will describe how various observable IR and UV phenomena can be canonically extracted directly from celestial amplitudes. Moreover, a manifestly Lorentz covariant formulation of scattering constraints is necessary for their direct application to celestial amplitudes. I will explain how constraints from Poincare symmetry, soft UV behavior of quantum gravity, and asymptotic symmetries are covariantly implemented in celestial amplitudes. |
Mar 17 2021
14:00 |
|
Dario Buttazzo
(INFN Pisa)
|
|
ABSTRACT: |
Mar 10 2021
14:30 |
Zoom
|
Guido Festuccia
(Uppsala Univesity)
|
Consistency of supersymmetric 't Hooft anomalies |
ABSTRACT: I will consider recent claims that supersymmetry is anomalous in the presence of a R-symmetry anomaly, revisit arguments that such an anomaly in supersymmetry can be removed and write down an explicit counterterm that accomplishes it. Removal of the supersymmetry anomaly requires enlarging the corresponding current multiplet. As a consequence the Ward identities for other symmetries that are already anomalous acquire extra terms. This procedure is impeded only when the choice of current multiplet is forced. We show how Wess-Zumino consistency conditions are modified when the anomaly is removed. A check that the modified Wess-Zumino consistency conditions are satisfied, and supersymmetry is unbroken, is possible via an explicit one loop computation using Pauli-Villars regulators. |
Mar 03 2021
14:00 |
|
Emanuele Gendy
()
|
|
ABSTRACT: |
Feb 24 2021
14:30 |
Zoom
|
Zoltan Bajnok
(Wigner Research Centre for Physics, Hungary)
|
From perturbative to non-perturbative in the O(4) sigma model |
ABSTRACT: Is it possible to derive non-perturbative contributions in a quantum field theory
knowing only the perturbative coefficients? We answer this question affirmatively
based on the careful analysis of the integrable two dimensional O(4) sigma model.
We investigate its ground state energy in a magnetic field, for which integrability
provides an exact linear integral equation. By cleverly expanding this equation
we could calculate a large number of very percise, factorially growing perturbative
coefficients. By investigating their asymptotical behaviour on the Borel plane we
managed to reveal a nice resurgence structure leading to the first few exponentially
supressed non-perturbative terms of the ambiguity free trans-series. We checked
our results against the direct numerical solution of the exact integral equation
and find complete agreement.
Based on 2011.12254 and 2011.09897 |
Feb 10 2021
16:00 |
Zoom
|
Sahand Seifnashri
(Stony Brook University, SCGP)
|
Non-invertible Symmetries and Confinement in 2d Adjoint QCD |
ABSTRACT: We will discuss the notion of "non-invertible symmetries" that generalize group-like symmetries in QFTs. Using these generalized symmetries we prove the deconfinement of the fundamental quark in 2d massless adjoint QCD. When the adjoint quark has a small mass the theory confines and the non-invertible symmetries are softly broken. We use them to analytically compute the tension of the confining strings. We will also consider the symmetric quartic fermion deformations that are protected by the non-invertible symmetries, thus violating the ordinary notion of naturalness. |
Jan 13 2021
15:00 |
Zoom
|
Petr Kravchuk
(IAS Princeton)
|
Light-ray operators, detectors, and OPEs |
ABSTRACT: In this talk I will review the recent developments connected to light-ray operators in conformal field theories.
Light-ray operators are non-local operators which perform an analytic continuation of the usual local operators
in spin. In CFTs they are connected to the recently discovered Lorentzian inversion formula
and to some interesting representation theory. Furthermore, they can be interpreted as asymptotic observables,
generalizing event shapes such as energy-energy correlators. Finally, I will discuss how they control
the small-angle limit of energy-energy correlators. |
May 20 2020
15:00 |
Zoom (email F.Benini to obtain the password)
|
C. P. Herzog
(King's College London)
|
Graphene and Boundary Conformal Field Theory |
ABSTRACT: The infrared fixed point of graphene under the renormalization group
flow is a relatively under studied yet important example of a boundary
conformal field theory with a number of remarkable properties. It has
a close relationship with three dimensional QED. It maps to itself
under electric-magnetic duality. Moreover, it along with its
supersymmetric cousins all possess an exactly marginal coupling -- the
charge of the electron. I will review past work on this model and
also discuss my own contributions which have focused on understanding
the boundary contributions to the anomalous trace of the stress tensor
and their role in helping to understand the structure of boundary
conformal field theory. I will also present some results on the
hemisphere partition function for supergraphene, its duality
properties, and an exact computation of the conductivity at arbitrary
values of the interaction strength. |
Apr 22 2020
14:30 |
SISSA - room 005
|
Fabrizio Del Monte
(SISSA)
|
TBA |
ABSTRACT: |
Mar 03 2020
14:30 |
SISSA - 005
|
Guido Martinelli
(Rome - Sapienza (Note it's a Tuesday!))
|
TBA |
ABSTRACT: |
Feb 26 2020
14:30 |
SISSA - room 005
|
Camila Machado
(PRISMA+ (Mainz))
|
Effective Field Theories and Scattering Amplitudes (CANCELED) |
ABSTRACT: On-shell methods have been transforming our understanding of perturbative physics. The main idea is to get rid of non-linear field redefinitions and (off-shell) gauge redundancy and to work directly with physical amplitudes. Although not obvious, this can shed light on the consistency of an EFT and other properties. Despite the tremendous progress, most on-shell methods apply only to theories with massless particles, such as gluons or gravitons where a convenient formalism to extend these methods to particles with arbitrary spins/masses was proposed recently, much remains to explore. In particular, this can be used to study the so called Standard Model EFT (SMEFT). In this talk, I will give an introduction to the massive spinor formalism and I will describe how this can be used to write the tree-level SMEFT in the Warsaw basis. In addition, I will discuss how this can also be applied to study BSM scenarios. |
Feb 19 2020
14:30 |
|
Matteo Sacchi
(Università Bicocca, Milano)
|
The E[USP(2N)] theory: E-string on tori and 4d mirror-like dualities |
ABSTRACT: |
Feb 05 2020
11:30 |
IFPU - room 205
|
Andrea Tesi (at IFPU!!!)
(INFN Firenze)
|
Gravitational Waves from Supercool Axions |
ABSTRACT: I will discuss the dynamics of the Peccei-Quinn (PQ) phase transition for the QCD axion. In weakly coupled models the transition is typically second order except in the region of parameters where the PQ symmetry is broken through the Coleman-Weinberg mechanism. In strongly coupled realizations the transition is often first order. I will show examples where the phase transition leads to strong supercooling lowering the nucleation temperature and enhancing the stochastic gravitational wave signals. The models predict a frequency peak in the range 100-1000 Hz with an amplitude that is already within the sensitivity of LIGO and can be thoroughly tested with future gravitational wave interferometers. |
Feb 05 2020
14:30 |
ICTP - Stasi Room
|
Cumrun Vafa (at ICTP!!)
(Harvard)
|
New Swampland Conjectures |
ABSTRACT: |
Jan 15 2020
14:30 |
SISSA - 005
|
Fabrizio Nesti
(L'Aquila)
|
Left Right Symmetry |
ABSTRACT: While the Standard Model Higgs mechanism is proving triumphant in
explaining the masses of elementary particles such as gauge bosons and
charged fermions, a similar understanding for the masses of neutrinos is
still missing. I review the possibility that parity is restored at accessible
collider energies as in the minimal Left-Right Symmetric Model, which directly
offers a framework for the neutrino mass mechanism.
I review the bounds from flavour changing and CP-violating observables,
mainly from K mesons and B in the future, and describe the recent assessment
of correlation between Kaon CP violation and strong CP violation for the neutron EDM.
I close by reviewing the possible phenomenology of low scale Lepton-Number
Violation in the interplay between different phenomena: from neutrinoless
double-beta decay, to production at LHC of new gauge bosons, and possible
decays of the Higgs bosons with displaced vertices, all contributing to probe
the neutrino mass origin. |
Dec 11 2019
14:30 |
SISSA - room 005
|
João Penedo
(Tecnico Lisboa)
|
Flavour symmetries from modular invariance |
ABSTRACT: The interest in explaining fermion masses and mixing via a modular symmetry
has been revived in the last couple of years. In such a scheme, finite quotients
of the modular group take the role of discrete non-Abelian flavour symmetries.
In this seminar, I will give an overview of recent results, focusing also on the consistent
implementation of a generalised CP symmetry within modular-invariant models. |
Nov 28 2019
14:30 |
SISSA - room 137
|
Oliver Fischer
(Karlsruhe Institute of Technology (KIT))
|
A falsifiable explanation of the MiniBooNE anomaly |
ABSTRACT: The MiniBooNE experiment was designed to test the LSND anomaly, and it found evidence for neutrino oscillations that contradict the global data set on short baseline experiments.\r\nIn this talk I will give a non-standard explanation for the observed so-called “electron-like signal” that revolves around a BSM particle, a heavy neutrino with a mass of a few hundred MeV. \r\nThis particle is produced from kaon decays after the proton beam-target interaction and it decays inside the detector into a single photon and a light neutrino.\r\nBeing heavy, the new neutrinos arrive later than the light ones, such that their decays give rise to electron-like events with a very characteristic time spectrum that cannot be mimicked by the light neutrinos. |
Nov 26 2019
14:30 |
SISSA - room 137
|
Francesco Capozzi
(Max Planck Institut - Heidelberg)
|
Frontiers in Neutrino Oscillations: Precision and New Phenomena |
ABSTRACT: Despite being a well established phenomenon, neutrino oscillations are extremely important\r\nin both particle physics and astrophysics. \r\nOn the one hand, the mass-mixing parameters governing oscillations are still being measured, giving insights \r\non the underlying flavor symmetries and CP violation in the lepton sector. The level of precision reached in these \r\nmeasurements poses unprecedented problems and opportunities: extremely refined statistical analysis of current \r\nand prospective data are now required. At the same time there is an increased sensitivity to physics beyond the \r\nStandard Model. \r\nOn the other hand, neutrinos are now commonly used as messengers from astrophysical sources. In this case a \r\nfull understanding of oscillations is mandatory for a precise characterization of the sources. However, in very dense \r\nastrophysical environments (core-collapse supernovae, neutron star mergers, ...), flavor evolution is still under theoretical \r\ninvestigation, even in the context of the Standard Model, where new collective oscillation effects can occur.\r\nIn my talk I will review the current issues, recent advancements and future prospects for both frontiers: precision and \r\nnew physical phenomena. |
Nov 25 2019
15:00 |
SISSA - room 137
|
Stefano Gariazzo
(IFIC - Valencia)
|
Relic neutrinos, from A to Z |
ABSTRACT: A background radiation of relic neutrinos, originated during the early phases of the Universe expansion, is predicted by the standard cosmological model, but has never been confirmed by a direct measurement. Indirect probes already provide information on relic neutrinos, but future direct detection experiments will give us many more details to understand the properties of these extremely elusive particles. In this seminar, I will review some of the aspects related to the theoretical study of relic neutrinos properties including standard and non-standard physics: I will talk about their momentum distribution function, local number density, and the effect of additional neutrino states. Finally, I will discuss what future direct detection experiments, such as PTOLEMY, can teach us. |
Nov 20 2019
14:30 |
005
|
Marco Serone
(SISSA)
|
Conformality Loss, Walking, and 4d Complex CFTs at Weak Coupling |
ABSTRACT: Four-dimensional gauge theories can flow in the infrared to non-trivial conformal field theories.
It has been conjectured that conformality can be lost because of merging of two nearby fixed points that move into the complex plane, and that a walking dynamics governed by scaling dimensions of operators defined at such complex fixed points can occur. Controlled, parametrically weakly-coupled, and ultraviolet-complete 4d gauge theories that explicitly realize this scenario are presented. |
Nov 13 2019
14:30 |
005
|
Gabriel Francisco Cuomo
(EPFL, Lausanne)
|
The epsilon expansion meets semiclassics |
ABSTRACT: In this talk I will study the scaling dimension of the lightest operator of charge $n$ in the $U(1)$ model at the Wilson-Fisher fixed point in $4-varepsilon$ dimensions.
Even for a perturbatively small fixed point coupling $lambda$, standard perturbation theory breaks down for sufficiently large $lambda n$. Treating $lambda n$ as fixed for small $lambda $, I will show that the scaling dimension can be successfully computed through a semiclassical expansion around a non-trivial trajectory, resulting in a series in the coupling whose coefficients are fixed functions of $lambda n$.
I will discuss explicitly the computation of the first two orders in the expansion. The result, when expanded at small $lambda n$, perfectly agrees with all available diagrammatic computations. The asymptotic at large $lambda n$ reproduces the systematic large charge expansion, recently derived in CFT.
Similar results can be derived in the $U(1)$ model in $3-varepsilon$ dimensions. I will briefly comment on the application of similar ideas in the calculation of other observables, such as three-point functions of charged operators. |
Oct 23 2019
14:30 |
Room - 005 - SISSA
|
Ilaria Brivio
(U. Heidelberg, ITP)
|
The Neutrino Option |
ABSTRACT: The "Neutrino Option" is a scenario where the SM Higgs potential is generated radiatively in a type-I seesaw model, starting from an approximately conformal condition in the UV.
I will show which regions of the parameter space are simultaneously consistent with this hypothesis and the generation of realistic neutrino masses, and I will discuss how leptogenesis can be realized within this setup. |
May 29 2019
14:30 |
SISSA 005
|
Victor Guada
(Institut Joef Stefan - Ljubljana)
|
Multi-Field False Vacuum Decay: Polygonal Bounce |
ABSTRACT: The decay of a false vacuum is a complex problem which appears in different contexts of physics, as in particle physics, cosmology, baryogenesis, and condensed matter physics. This first-order phase transitions in QFT arise from an abrupt decay of an excited state of false vacuum into an energetically more favorable minimum of energy through bubble nucleation, as in boiling superheated fluid.
The features of such decay processes have long been understood and developed in seminal works for single scalar field theories with metastable minima (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.15.2929). However, the problem complicates significantly when an arbitrary number of fields is considered. Most new physics models contain additional scalar fields for theories beyond the SM but such models usually possess a nontrivial vacuum structure with a number of metastable and potentially long-lived ground states. Finding the path in field space and computing the lifetime of such metastable states in general potentials are still challenging and not completely understood.
This talk is based on the paper (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.99.056020), which presents a new semi-analytical approach to compute such tunneling decay rate with any number of scalar fields and space-time dimensions. It is based on exact analytical solutions of piecewise linear potentials with many segments that describe any given potential up to a desired precision. Contributions beyond the linear order as well as the generalization to more fields are considered and computed through analytical linear expansions. Thereby, this approach provides a fast and robust method for evaluating tunneling decay in theories with multiple scalar fields. |
May 15 2019
14:30 |
|
Rashmish K. Mishra
(Pisa, Scuola Normale Superiore - INFN Pisa)
|
Theoretical and experimental considerations of a multi-brane world |
ABSTRACT: Simple generalizations of well known BSM scenarios can lead to dramatic signals at colliders, providing interesting theoretical playgrounds and motivating new methods to isolate non-standard experimental signals. In this talk, I will consider warped extra-dimensional models with multiple branes in the IR and discuss the theoretical possibilities and related collider signals. The resulting signals require dedicated strategies at LHC, with varying sophistication. In addition, these strategies are relevant for a broad class of BSM scenarios. A specific realization of this multi-brane setup presents a way to study conformal dark sectors, with non-gravitational interactions to the SM. Motivating the minimal interaction needed to the conformal dark sector, I will discuss the collider and cosmological bounds on this scenario. |
May 08 2019
14:30 |
SISSA 005
|
Ivan Garozzo
(Milano Bicocca)
|
3d N=2 dualities with monopole superpotentials and branes |
ABSTRACT: The study of three dimensional infrared dualities is a popular subject and allows to
investigate non-perturbative phenomena in Quantum Field theory. A large class of
interesting dualities involves theories with four supercharges, whose richness is
due to monopole operators parametrising the Coulomb branch.
In this talk I discuss recent aspects of dualities between gauge theories with unitary
and symplectic groups involving monopole superpotentials, focusing on matching
their moduli spaces and showing the consistency of their RG flow to the IR.
Moreover, I discuss the brane engineering of the aforementioned dualities, showing
that in order to reproduce the quadratic monopole one has to involve exotic
orientifold configurations and twisted affine algebras.
Moreover, the D-brane realisation provides a classification principle for 3d N=2
dualities with monopole superpotentials, allowing to reproduce known dualities and
finding new ones previously overlooked in the literature. |
Apr 24 2019
14:30 |
Room 005
|
Roberto Vega Morales
(University of Granada)
|
TBA |
ABSTRACT: TBA |
Apr 17 2019
14:30 |
SISSA room 137
|
Pedro Martinez
(La Plata University)
|
Holographic excited states in AdS black holes |
ABSTRACT: I will present and describe the properties of a set of excited states of a finite temperature CFT via holographic methods. These excited states can be non-pertubately defined in both theories and turn out to be coherent excitations over the TFD vacuum in the large N limit, for which we can compute its eigenvalues.
First, I will review the problems arising from a pure real-time formulation of AdS/CFT and how these can be solved in a complex-time formulation of the duality over Schwinger-Keldysh paths. This framework, known as SvR prescription, will render our prescription for excited states natural.
I will then build a geometry dual to a particular Schwinger-Keldysh path for a finite temperature formalism made out of Euclidean and Lorentzian pieces of AdS-BHs, which is an interesting problem on its own, regarding the analyticity of fields inside the bulk. This allows both to observe a real time version of the Hawking Page transition as well as to study the excited states at finite temperature. |
Apr 10 2019
14:30 |
Room 005
|
Ennio Salvioni
(TUM Munich)
|
Dark matter shifts away from direct detection |
ABSTRACT: The dark matter (DM) could emerge along with the Higgs as a composite pseudo-Nambu-Goldstone boson with decay constant ~TeV. This type of WIMP is especially interesting because its leading interaction with the Standard Model, the derivative Higgs portal, has the correct annihilation strength for thermal freeze-out if the DM has weak-scale mass, but is negligible in direct detection experiments due to the small momentum transfer. The explicit shift symmetry breaking required to generate radiatively the DM mass, however, also introduces non-derivative DM interactions. I will discuss the phenomenology of scenarios where the pattern of explicit symmetry breaking naturally suppresses the direct detection cross section beyond the current experimental sensitivity. Based on 1809.09106, and work in progress. |
Feb 06 2019
14:30 |
Room 005
|
Rakhi Mahbubani
(ITPP Lausanne)
|
'Tuning in' to dark matter via indirect detection |
ABSTRACT: We show that the presence of Coulombic resonances at finite energy could lead to the enhancement of the dark matter annihilation cross section at specific non-zero velocities correlated with the mass splitting between the dark matter pair and that of the resonance.If one of these resonant velocities approximately matches the velocity of dark matter in our local neighbourhood, we would see this enhancement in indirect-detection measurements, such as the measurements of the continuum photon spectrum made by Hess and Fermi. We explore this effect in the context of pure Higgsino and Wino dark matter with a variable splitting between charged and neutral components, controlled by the Wilson coefficient of a higher-dimension operator. For electroweak WIMPs a relevant and appreciable enhancement from Coulomb resonances requires tuning the charged-neutral splitting to be of order the Coulomb binding energies. This leads to strong exclusions of Higgsino dark matter with charged-neutral splittings in the narrow ranges (2, 2.5) and (8.5, 10.5) MeV. In contrast, by decreasing the charged-neutral splitting for the thermal Wino, we can move the Yukawa resonance away from the thermal relic mass, decreasing the annihilationn cross section to a level that is comfortably compatible with existing measurements in the window (25, 35) MeV. |
Jan 11 2019
14:30 |
Room 005
|
Lorenzo Di Pietro
(Perimeter Institute)
|
Quantum Field Theory in AdS at finite coupling |
ABSTRACT: The talk is based on https://arxiv.org/abs/1810.04185. I will start by giving some general motivations for why QFT in AdS is interesting. Then I will focus on the example of large N vector models. I will explain how we computed the AdS correlators in these theories by requiring the absence of spurious double-trace contributions in the boundary correlators. I will move on to discuss the physics described by these correlators. In particular, in the bosonic (fermionic) theory we can see the AdS analogue of a resonance (bound state) in the flat-space scattering amplitude. If time permits, I will also discuss the critical theories in AdS and the boundary-cft data encoded in the AdS correlators. |
Dec 19 2018
14:30 |
Room 005
|
Denis Karateev
(EPFL)
|
Harmonic analysis and mean field theory |
ABSTRACT: I will introduce and discuss the harmonic analysis on the d-dimenional conformal group. I will apply this analysis to a specific CFT called the Mean Field Theory (MFT), aka Generalized Free Theory. I will derive a formula for the MFT data (OPE coefficients and scaling dimensions) written in terms of the basic ingredients of harmonic analysis such as shadow coefficients, three-point pairings and the Plancherel measure. I will finally introduce a method based on weight-shifting operators which allows to compute efficiently these ingredients for any spin. |
Dec 05 2018
14:30 |
Room 137
|
Darius Faroughy
(J. Stefan Institute, Ljubljana)
|
Direct searches motivated by the recent B-anomalies |
ABSTRACT: We discuss the physics case for direct searches at the LHC motivated by the B-physics anomalies. After correlating semi-tauonic B decays with di-tau tails at the LHC, and discussing the possible models solving the B-anomalies, we show how existing LHC data exclude most beyond the SM scenarios except for a handful of leptoquark (LQ) models. |
Nov 28 2018
14:30 |
Room 005
|
Brando Bellazzini
(IPhT Saclay)
|
Charting the space of (in)consistent EFTs |
ABSTRACT: In this talk I will discuss which Effective Field Theories (EFTs) may arise from underlying microscopic theories that have a unitarity, analytic, and crossing-symmetric S-matrix. I will show various applications in particle physics and cosmology, including recent theoretical constraints on galileons, massive gravity, and massive higher-spin theories. |
Nov 21 2018
14:30 |
SISSA - Room 5
|
Amit Sever
(CERN)
|
Non-planar Scattering amplitudes in N=4 SYM theory |
ABSTRACT: |
Nov 14 2018
14:30 |
Room 005
|
Shankha Banerjee
(IPPP Durham)
|
Constraining certain Higgs couplings at the HL-LHC and beyond |
ABSTRACT: In this talk, I will review the present status of the Higgs boson's properties since its discovery in 2012. I will focus on the measurements of several Higgs couplings, upon considering standard decay modes, in the context of an effective field theory. I will also discuss the possibility of strongly constraining the couplings affecting the triple gauge boson vertices upon studying the ZH channel in the boosted Higgs regime. I will show the potential of the High luminosity run of the LHC (HL-LHC) and the future 100 TeV FCC-hh machine, to constrain such couplings to stronger degrees than LEP had constrained earlier. Finally, I will discuss various studies pertaining to the measurement of the Higgs trilinear coupling at the HL-LHC and at a future 100 TeV collider. |
Oct 24 2018
14:30 |
Room 005
|
Carl Turner
(DAMTP)
|
Landau Levels, CFTs and Duality |
ABSTRACT: We ask what happens to three dimensional CFTs with a U(1) symmetry when we subject them to a magnetic field. We will also think about how this relates to non-relativistic field theory, and what it can tell us about Chern-Simons-matter dualities. This will direct us to think about fusion rules in Chern-Simons theory, which in turn can help us gain insight into the nature of operator correspondences. We will also see what goes wrong when we exceed the flavour bounds believed to restrict these dualities. |
Oct 03 2018
14:30 |
Room 005
|
Masazumi Honda
(Weizmann Institute)
|
Resurgence and Lefschetz thimble in 3d N=2 supersymmetric Chern-Simons matter theories |
ABSTRACT: We study a certain class of supersymmetric (SUSY) observables in 3d N=2 SUSY Chern-Simons (CS) matter theories
and investigate how their exact results are related to the perturbative series with respect to couplingconstants given by inverse CS levels.
We show that the observables have nontrivial resurgent structures by expressing the exact results as a full transseries consisting of perturbative and non-perturbative parts.
As real mass parameters are varied, we encounter Stokes phenomena at an infinite number of points, where the perturbative series becomes non-Borel-summable due to singularities on the positive real axis of the Borel plane.
We also investigate the Stokes phenomena when the phase of the coupling constant is varied.
For these cases, we find that the Borel ambiguities in the perturbative sector are canceled by those in nonperturbative sectors and end up with an unambiguous result which agrees with the exact result even on the Stokes lines.
We also decompose the Coulomb branch localization formula, which is an integral representation for the exact results, into Lefschetz thimble contributions and study how they are related to the resurgent transseries.
We interpret the non-perturbative effects appearing in the transseries as contributions of complexified SUSY solutions which formally satisfy the SUSY conditions but are not on the original path integral contour.
This talk is based on arXiv:1604.08653, 1710.05010 and 1805.12137. |
Sep 26 2018
14:30 |
SISSA - Room 5
|
Sergio Cecotti
(SISSA)
|
Theta-problem and the String Swampland |
ABSTRACT: |
Jun 20 2018
14:30 |
Room 005
|
Giovanni Grilli di Cortona
(University of Sau Paulo)
|
Collider phenomenology of Hidden Valley models with semivisible jets |
ABSTRACT: Many New Physics models contain particles that are charged under both Standard Model and Hidden Valley gauge groups, yet very little effort has been put into establishing their experimental signatures. I will provide a general overview of the collider phenomenology of spin 0 or 1/2 mediators with non-trivial gauge numbers under both the Standard Model and a single new confining group, with a focus on direct production with semivisible jets. For the mediators to be able to decay, a global U(1) symmetry must be broken. This is best done by introducing a set of operators explicitly violating this symmetry. I will show that there is only a finite number of such renormalizable operators and that the phenomenology can be classified into five distinct categories. I will also show that large regions of the parameter space are already excluded, while others are unconstrained by current search strategies. Finally I will discuss how searches could be modified to better probe these unconstrained regions by exploiting special properties of semivisible jets. |
Jun 13 2018
14:30 |
Room 137
|
Morimitsu Tanimoto
(Niigata University)
|
Towards minimal Flavor model via CP violation |
ABSTRACT: The recent data of T2K and NovA indicate the atmospheric neutrino mixing angle theta_23 to be near the maiximal one. The closer the observation this angle is to the maximal mixing, the more likely some flavor symmetry behind it. In order to confirm the flavor symmetry, it is adavantageous to consider the minimal number of parameters needed for reproducing the neutrino mixing angles and CP violating phase completely. I discuss the flavor model with A4 symmetry in the minimal scheme of flavons focusing on the CP violation. We also discuss the A4 symmetry as the modular group. |
Jun 06 2018
14:30 |
Room 005
|
Marco Serone
(SISSA)
|
lambda phi^4 Theory I: The Symmetric Phase Beyond NNNNNNNNLO |
ABSTRACT: |
May 30 2018
14:30 |
Room 005
|
Josh Ruderman
()
|
Thermal Relic Exceptions |
ABSTRACT: Dark matter may be a thermal relic: a particle that had a temperature in the early Universe. The observed abundance of dark matter can be explained by a thermal relic that annihilates with a weak scale cross section. This so-called WIMP miracle points to a dark matter mass near the TeV scale. However, dramatic improvements in the sensitivity of direct detection experiments targeting TeV scale dark matter, and the lack of a discovery so far, motivates exploration beyond the WIMP. I will discuss how simple deformations to the usual assumptions underlying the WIMP miracle point to thermal relic dark matter with an exponentially lighter mass, and different interactions, than the WIMP. I will introduce models where dark matter annihilates into heavier states (forbidden dark matter) and models where the dark matter abundance is set by inelastic scattering instead of annihilations (coscattering"). Each of these scenarios points to experimental prospects that differ from those of the WIMP. |
May 16 2018
14:30 |
Room 005
|
Jisuke Kubo
(Kanazawa University)
|
Dark Matter Genesis as an Origin of Gravitational Wave Background |
ABSTRACT: We assume that the electroweak scale is generated
in a hidden sector which is described by a non-abelian gauge theory.
The non-perturbative
effect in the hidden sector generates dark matter as well.
Since this dynamical scale genesis appears as a first-order
phase transition at finite temperature, it can produce
a gravitational wave background. |
Apr 11 2018
14:30 |
Room 005
|
Jose Espinosa
(IFAE Barcellona)
|
Implications of Higgs Vacuum Metastability |
ABSTRACT: The Standard Model electroweak vacuum lies very close to the boundary
between stability and metastability, with the last option being the most likely.
I will discuss a) the interplay of this so-called "near-criticality" with physics
beyond the Standard Model including possible Planckian effects;
b) the main challenges that the survival of the electroweak vacuum faces
during the evolution of the Universe, and c) possible signatures of this
instability showing how Higgs fluctuations during inflation might provide dark matter
in the form of primordial black holes as well as a background of potentially
observable gravitational waves. |
Apr 10 2018
14:30 |
Room 137
|
Kallol Sen
(University of Tokyo)
|
Perturbations in CFTs |
ABSTRACT: I will discuss the aspects of the perturbations in CFTs from two different points of view. The first point of view is rephrasing the usual perturbation in QFT in the modern language of Conformal Bootstrap. More specifically I will discuss the epsilon-expansion in phi^4 theory from the bootstrap point of view. The second point of view is to try to form a statement about the deformation of a strongly coupled CFT by a marginal operator. |
Mar 14 2018
12:00 |
Room 005
|
Valentina De Romeri
(Valencia University)
|
Minimal extensions of the SM with sterile neutrinos: impact on cLFV and LNV processes |
ABSTRACT: Massive neutrinos and their mixings provide the first evidence of flavour violation in the leptonic sector and open a whole window on many new processes, within reach of high-energy and high-intensity facilities. An observation of charged lepton flavour violation (cLFV) processes will undoubtedly point towards the existence of New Physics. Analogously, if observed, lepton number violating (LNV) processes are a clear sign of New Physics which indirectly hint for a Majorana nature of neutrinos. In this talk I will firstly briefly review the experimental status of cLFV searches. Then I will discuss the potential of minimal extensions of the Standard Model (SM) via heavy sterile fermions concerning an extensive array of observables. Among others, I will discuss cLFV processes like three-body decays, nuclear-assisted processes and rare LFV Z decays and LNV processes like neutrinoless meson and tau decays. |
Mar 07 2018
14:30 |
Room 005
|
Simone Alioli
(Universit di Milano Bicocca)
|
High-energy probes of the SM EFT at the LHC and future colliders |
ABSTRACT: New physics, that is too heavy to be produced directly, can leave
measurable imprints on the tails of kinematic distributions.
We use energetic SM processes to perform novel measurements of the
Standard Model (SM) Effective Field Theory, showing
that jets and leptonic distributions are sensitive to dimension 6
operators that modify the propagators at high energies.
The dominant effect is constructive or destructive interference with
SM jet and Drell-Yan production. We compare differential higher-order order predictions to public 7 TeV jet and di-lepton data, including scale, PDF, and experimental uncertainties and their respective correlations.
We show how the bounds on new physics can already be improved with current data and project the reach of future 13, 27 and 100 TeV
measurements. |
Feb 07 2018
14:30 |
Room 005
|
Ye-Ling Zhou
(IPPP Durham)
|
Phenos of flavour symmetries |
ABSTRACT: Non-Abelian discrete flavour symmetries have been widely used to
explain large mixing angles measured by neutrino oscillation experiments.
Imposing flavour symmetries into the lepton sector will not only predict
the lepton mixing, but also trigger other flavour-dependent
phenomenological signatures. In this talk, I will discuss how these
symmetries contribute to rare decays of charged leptons and non-standard
interactions in neutrino experiments. Unique features of non-Abelian
discrete symmetries in these experiments will be specified. |
Jan 31 2018
14:30 |
Room 005
|
Dumitru Ghilencea
(IFIN-HH Bucharest)
|
Manifestly scale-invariant regularization and quantum implications |
ABSTRACT: Using a perturbative approach, I explore the possibility that scale symmetry is a quantum symmetry broken spontaneously. Following the original idea of Englert et al, a classical scale-invariant model is considered and it is shown how to compute quantum corrections while preserving this symmetry, with the DR subtraction scale generated by the dilaton field (after spontaneous breaking). Evanescent interactions ($proptoepsilon$) between the visible and hidden (dilaton) sector, dictated by the scale invariance of the action in $d=4-2epsilon$, generate at the quantum level new effective operators of non-polynomial type, suppressed by powers of the dilaton field. Quantum corrections to the scalar potential are presented in some examples, including a scale invariant version of the Standard Model extended by the dilaton. |
Jan 17 2018
14:30 |
Room 005
|
Sergio Cecotti
(SISSA)
|
Geometrical classification of 4d N=2 SCFTs |
ABSTRACT: |
Dec 20 2017
14:30 |
SISSA - Room 5
|
Lorenzo Di Pietro
(Perimeter Institute)
|
Loops in AdS from Hamiltonian approach |
ABSTRACT: |
Dec 18 2017
14:30 |
Room 005
|
Marco Nardecchia, David Marzocca and Alfredo Urbano
(INFN Trieste)
|
Presentation of new INFN staff |
ABSTRACT: |
Dec 06 2017
14:30 |
Room 005
|
Orestis Loukas
(University of Bern)
|
Accessing the CFT spectrum at large global charge |
ABSTRACT: Studying strongly coupled CFTs with some global symmetry in sectors where the associated global charge is large, often leads to an effective action which is weakly coupled. In this regime, the computation of anomalous dimensions and fusion coefficients becomes perturbatively meaningful. I review our recent progress in understanding the large-charge sectors of classes of scalar CFTs in three dimensions, both at the level of the linear as well as non-linear sigma model. Additionally, I comment on the verification of the analytic prediction via lattice simulations. |
Dec 01 2017
14:30 |
SISSA - Room 137
|
Jesus Montero
(Oviedo Univ.)
|
The AdS5 non-Abelian T-dual of Klebanov-Witten as a N=1 linear quiver |
ABSTRACT: We study an AdS5 solution constructed using non-Abelian T-duality, acting on the Klebanov-Witten background. We show this can be described in terms of a D4-NS5-NS5 brane set-up dual to a linear quiver with two tails of gauge groups of increasing rank, generalizing the constructions discussed by Bah and Bobev. The central charges computed both holographically and using a-maximization are shown to agree. Our result exhibits n^3 scaling with the number of five-branes, suggesting an eleven-dimensional interpretation in terms of M5-branes. Based on 1705.09661 |
Nov 29 2017
14:30 |
Room 005
|
Christopher Couzens
(King's College London)
|
AdS3/CFT2 and F-theory |
ABSTRACT: In this talk we consider holographic duals of F-theory solutions to 2d SCFT's. We approach the problem by classifying a particular class of solutions of type IIB supergravity with AdS_3 factors and varying axio-dilaton. The class of solutions we discuss consist of D3 and 7-brane configurations and naturally fall into the realm of F-theory. We prove that for (0,4) supersymmetry in 2d the solutions are essentially unique and we match the holographic central charges to field theory results. We comment on future directions, including AdS_3 solutions of F-theory, preserving different amounts of supersymmetry. |
Nov 24 2017
14:30 |
Room 005
|
Post-Doc Day
()
|
Post-Doc Day |
ABSTRACT: |
Nov 22 2017
14:30 |
SISSA
|
Anton Nedelin
(Bicocca)
|
T[U(N)] duality web: mirror symmetry and gauge/CFT correspondence |
ABSTRACT: In this talk I will review recently obtained correspondence
between
partition functions of 2d GLSM and certain correlators of Toda CFT. To
illustrate this
correspondence I will consider particular example: the partition function
of 3d
T[U(N)] theory. I will start by reviewing mirror self-duality of this class
of theory and will
briefly derive correspondence between its holomorphic blocks and
Dotsenko-Fateev
representation of the correlators in q-deformed Toda CFT. Finally I will
show how
upon the circle reduction 3d mirror symmetry reduces to correspondence
between
the partition function of certain 2d N =(2,2) quiver theory and Toda CFT
correlators. |
Nov 08 2017
16:00 |
SISSA - Room 5
|
Pietro Antonio Grassi
(UPO - Alessandria)
|
Introduction to Integral Forms and Application to Physics - Integration on Supermanifolds |
ABSTRACT: The geometric integration theory for differential forms is extended to supermanifolds.The complex of differential form is enriched to include the integral forms. Applications to Supersymmetric Quantum Field Theories and String Theory is considered.The technique permits an interpolation between all superspace formulations of several theories. |
Oct 18 2017
14:30 |
Room 137
|
Bruno Le Floch
(PCTS - Princeton)
|
Orbifolds of 4d N=2 supersymmetric gauge theories |
ABSTRACT: After recalling how some 4d N=2 gauge theories arise from
reductions of 6d N=(2,0) superconformal theories on a Riemann surface, I
will discuss two discrete quotients with codimension 2 orbifold
singularities. In the first case the orbifold acts by rotations around
one plane of the 4d N=2 theory; this is related to a Gukov-Witten
surface operator that imposes a monodromy around that plane. We deduce
instanton partition functions in the presence of surface operators;
interestingly, instantons can fractionalize. In the second case the
orbifold acts by reflection on the 4d theory and the Riemann surface.
We learn how boundaries are encoded in the AGT correspondence. We are
led to consider 4d N=2 quiver theories where some vector multiplets
live on a hemisphere and others on a projective space. |
Oct 04 2017
14:30 |
Room 005
|
Mahmoud Safari
(INFN Bologna)
|
Multicritical Box^k scalar theories |
ABSTRACT: We employ perturbative RG in the functional form along with epsilon-expansion to study multicritical single-scalar field theories with higher derivative kinetic terms.
We focus on those with a Z_2 symmetric critical point, and depending on the upper critical dimension and the number of derivatives in the kinetic term we distinguish two types of theories which show qualitatively different features.
We discuss each class in turn and extract some scaling dimensions and OPE coefficients at LO or NLO in epsilon. As crosscheck we obtain most of these results making use of the Schwinger-Dyson equations
and assuming conformal symmetry. Whenever available we also compare our results with those obtained using other approaches. |
Jun 14 2017
16:00 |
Room 137
|
Massimo Taronna
(Brussel University)
|
Spinning Witten Diagrams |
ABSTRACT: We develop a systematic framework to compute the conformal partial wave expansions (CPWEs) of tree-level four-point Witten diagrams with totally symmetric external fields of arbitrary mass and integer spin in AdS_{d+1}. Employing this framework, we determine the CPWE of a generic exchange Witten diagram with spinning exchanged field. As an intermediate step, we diagonalise the linear map between spinning three-point conformal structures and spinning cubic couplings in AdS. Using this map we can explore the emergence of bulk locality. |
May 24 2017
16:00 |
Room 137
|
Francesco Benini
(SISSA)
|
Dualities and Anomalies in (2+1)D Quantum Field Theories |
ABSTRACT: In this talk I will present new conjectured dualities that relate gauge theories with scalars or fermions in 2+1 dimensions. The dualities give interesting predictions about the infrared dynamics of those theories. I will also discuss some 't Hooft anomalies in (2+1)D, and anomaly matching for those theories. |
Apr 27 2017
16:00 |
Room 005
|
Ramona Grober
(Durham University, IPPP)
|
Higgs pair production and the trilinear Higgs self-coupling |
ABSTRACT: TBA |
Apr 05 2017
16:00 |
Room 005
|
Rodolfo Russo
(QMW - London)
|
Do black hole microstates carry multipole charges? |
ABSTRACT: Some supersymmetric black holes can be understood in string theory as bound states of D-branes, which provide, in principle, an explicit description of the black hole microstates. I will discuss how it is possible to derive the geometrical backreaction of the individual microstates by using this underlying string description and the supersymmetric quiver quantum mechanics that emerges at low energies. |
Mar 29 2017
16:00 |
Room 137
|
Florian Goertz
(CERN)
|
The Axiflavon |
ABSTRACT: |
Dec 07 2016
16:00 |
SISSA - Room 5
|
Latham Boyle
(Perimeter Institute)
|
What is the standard model of particle physics trying to tell us |
ABSTRACT: I will argue that the standard model contains a rather strong hint that -- instead of being simply an ordinary continuous 4D manifold -- spacetime is actually the product of a 4D manifold and a certain discrete/finite 6D space (i.e. there are 6D discrete/finite "extra dimensions"). I will introduce this idea and the evidence for it in simple way, and then discuss various outstanding puzzles and future directions |
Nov 30 2016
14:30 |
SISSA - Room 5
|
Postdoc Day
(SISSA)
|
|
ABSTRACT: |
Oct 05 2016
16:00 |
Room 005
|
Gabriele Ferretti
(Chalmers - Goteborg)
|
Gauge theories of partial compositeness |
ABSTRACT: |
Jul 06 2016
16:00 |
Room 005
|
Michael Jay Prez
(Universidad de Valencia)
|
Effective Theories of Flavour and the Non-Universal MSSM |
ABSTRACT: Flavour symmetries a la Froggatt-Nielsen mechanism provide arncompelling way to explain the hierarchy of fermionic masses and mixing angles in the Yukawa sector. In Supersymmetric extensions of the Standard Model where the breaking of Supersymmetry occurs at scales much larger than the breaking of flavour, this flavour symmetry must be respected not only by the Yukawas of the superpotential, but by the soft-breaking masses and trilinear terms as well. In this work we show that contrary to naive expectations, even starting with flavour blind soft breaking at a high scale, the effective theory obtained after integrating out the heavy mediator fields can be strongly non-universal.rnWe explore the phenomenology of these SUSY models after the latest LHCrnsearches for new physics. |
Jun 29 2016
9:00 |
Room 137
|
Second Year Students
(SISSA)
|
Progress report |
ABSTRACT: |
Jun 21 2016
16:00 |
Room 005
|
Francesco Riva
(CERN)
|
TBA |
ABSTRACT: |
Jun 08 2016
16:00 |
Room 005
|
Stefano Massai
(MPI - Munich)
|
Heterotic T-fects, F-theory and 6D SCFTs |
ABSTRACT: I will discuss several aspects of non-geometric, quantum heterotic compactifications to six dimensions. These are described by a fibration of the T-duality group whose degenerations define stringy, non-geometric defects (T-fects). By using heterotic/F-theory duality I will show how to classify the 6D (1,0) SCFTs which describe the low energy physics, uncovering a form of duality between non-geometric defects and geometric ADE singularities. This analysis uncovers features of the heterotic string away from the stable degeneration limit that have striking consequences for the geometry of the compactification space. |
May 26 2016
16:00 |
Room 004
|
Francesco D'Eramo
(UCSC - USA)
|
You can hide but you have to run: direct detection with vector mediators |
ABSTRACT: |
May 18 2016
16:30 |
ICTP - Euler Room (note unusual place!)
|
Malcolm Perry
(DAMTP)
|
TBA |
ABSTRACT: |
May 11 2016
16:00 |
Room 005
|
Dimitri Polyakov
(Sogang Univ. - South Korea)
|
Irregular Conformal Blocks and String Field Theory Solutions for Higher Spins |
ABSTRACT: |
May 09 2016
16:00 |
Big Meeting Room, 7th floor
|
Duccio Pappadopulo
(NYU)
|
Dark matters from hidden sectors |
ABSTRACT: |
May 04 2016
16:00 |
Room 005
|
Francesco Benini
(SISSA)
|
Black hole microstates in AdS from gauge theory |
ABSTRACT: One of the great successes of string theory, as a theory of quantum gravity,
is the explanation of the entropy of asymptotically-flat black holes. I will
present, instead, a counting of the microstates of certain black holes
in AdS4. The black holes have an holographic description as RG flows
from a 3D CFT to superconformal quantum mechanics, and the
counting of microstates proceeds via supersymmetric localization.
Along the way, we will define and compute an index for topologically
twisted theories, and propose an extremization principle to
determine the superconformal R-symmetry in quantum mechanics. |
Apr 06 2016
16:00 |
7th floor Big Meeting Room
|
Aleksandr Azatov
(ICTP)
|
Searching for new physics in the Higgs production in gluon fusion |
ABSTRACT: |
Mar 07 2016
16:30 |
Room 137
|
Apratim Kaviraj
(Bangalore, Indian institute of Science)
|
Conformal bootstrap from conformal block expansion |
ABSTRACT: |
Jan 13 2016
14:30 |
Room 005
|
Kazunobu Maruyoshi
(Imperial College - UK)
|
Anomalies of class $S_k$ theories from 6d |
ABSTRACT: TBA |
Nov 04 2015
16:00 |
Room 005
|
Alberto Mariotti
(VUB - Bruxelles)
|
Goldstini and the Z-peaked ATLAS excess |
ABSTRACT: I will first review the 3-sigma Z-peaked excess recently reported by the ATLAS collaboration and its possible interpretation in supersymmetric models. I will then discuss basic aspects of scenarios with multiple supersymmetry breaking sectors in gauge mediation. In particular I will explain how the low energy spectrum presents in this case extra light fermionic degrees of freedom, the pseudo-goldstini. I will derive their radiatively induced mass and describe their interactions with the MSSM particles. I will then show how a simplified model in the MSSM with pseudo-goldstini can accommodate the Z-peaked ATLAS excess without conflicting with other existing LHC searches. |
Oct 16 2015
14:00 |
Room 137
|
Rodolfo Russo
(QMW - London)
|
High energy gravitational scattering in string and field theory |
ABSTRACT: The scattering of high energy gravitons from a heavy object provides an interesting window on quantum gravity. In particular, the Regge limit is tractable both in string theory and at the level of field theory effective action. I'll compare the general results in these two frameworks and summarize how the causality constraints discussed in 1407.5597 arise. |
Jul 15 2015
16:00 |
Room 005
|
Lorenzo Di Pietro
(Weizmann Institute)
|
QED in d=3 from the epsilon-expansion |
ABSTRACT: |
Jun 10 2015
16:00 |
Room 005
|
Marcello Ciafaloni
(Universit di Firenze and INFN, sez. di Firenze)
|
Unified limiting form of graviton radiation at extreme energies |
ABSTRACT: After a plain introduction to the thought-experiment of transplanckian scattering, I present a new calculation of the associated graviton radiation, whose limiting form unifies the soft- and high-energy emission regimes. The graviton spin and its helicity transformation phases play a key role in determining both the elegant form of the gravitational coherent state and its new features - like deeply subplanckian characteristic energies and the reduction of fragmentation region and rapidity plateau around the Einstein deflection cone. |
Jun 03 2015
16:00 |
Room 137
|
Luigi Delle Rose
(Universit del Salento ed INFN, sez. di Lecce)
|
Vacuum stability in SM extensions with TeV scale right handed neutrinos |
ABSTRACT: We investigate the stability of the scalar potential in extensions of the Standard Model with right handed neutrinos at the TeV scale. In particular, we focus our analysis on two minimal extensions: the SM+inverse seesaw mechanism and the minimal U(1)' extension with type-I seesaw. These classes of models are potentially accessible at collider and flavour physics experiments. We show that the requirements of stability of the potential within the perturbative evolution under the renormalization group impose significant constraints on the Yukawa couplings of the right handed neutrinos. |
May 28 2015
15:00 |
Room 005
|
Morimitsu Tanimoto
(KITP & Niigata University)
|
Neutrinos and Discrete Symmetries of Flavors |
ABSTRACT: The neutrino oscillation experiments have revealed the neutrino mass differences and the two large neutrino mixing angles. These experimental data give us a big hint of the flavor symmetry. In this talk, we discuss the recent progress of the flavor models with the non-Abelian discrete symmetry and present phenomenological analyses of neutrino mixing and CP violation. |
May 20 2015
16:00 |
Room 005
|
Tirtha Sankar Ray
(IIT-Kharagpur (India))
|
The case for an unnatural composite Higgs model |
ABSTRACT: I will try to argue the case for an unnatural composite Higgs model motivated by gauge coupling unification, dark matter and testability at colliders. In the process I will also briefly review the present experimental constraints on the composite Higgs framework. |
May 06 2015
16:00 |
SISSA - Room 005
|
Marco Drewes
(Technische Universitt Mnchen)
|
Heavy neutrinos in cosmology and experiment |
ABSTRACT: Neutrinos are the only particles in the Standard Model of particle physics that have only been observed with left handed chirality to date. If right handed neutrinos exist, they could be responsible for several phenomena that have no explanation within the Standard Model, including neutrino oscillations, the baryon asymmetry of the universe, dark matter and dark radiation. In this talk I focus on the mass range between the pion mass and W mass and discuss implications for cosmology and particle physics. |
Apr 14 2015
14:00 |
Room 137
|
Luca Di Luzio
(Universit di Genova & INFN, sez. di Genova)
|
Accidental matter at the LHC |
ABSTRACT: In this talk I will discuss a class of weak-scale extensions of the Standard Model which automatically preserve its accidental and approximate symmetry structure at the renormalizable level and which are hence invisible to low-energy indirect probes. By requiring the consistency of the effective field theory up to scales of $10^{15}$ GeV and after applying cosmological constraints, we arrive at a finite set of possibilities. One of the most striking signatures of this framework is the presence of new charged and/or colored states which can be efficiently produced in high-energy particle colliders and which are stable on the scale of detectors. |
Apr 08 2015
16:00 |
Room 005
|
Roberto Franceschini
(CERN)
|
Top mass from the bottom (at NLO) |
ABSTRACT: In this talk I will briefly review the present status and motivations for an accurate measurement of the top quark mass. In particular I will outline future strategies and possible outcomes for a global combination of top quark masses measurement at hadron colliders. I will discuss the role that new types of measurement can play to clarify the issues of present precision top quark measurements.
In this context, I will present a distinctly new strategy for the top quark mass measurement based on properties of energy spectra, which can be applied both to b-jets and (under several guises) to B-hadrons observables, resulting in a sub-percent top quark mass determination. |
Mar 18 2015
16:00 |
Room 005
|
Francesco Sannino
(CP3 - Origins)
|
Rethinking Naturalness: The Interacting Ultraviolet Safe Behaviour of Gauge-Yukawa Theories |
ABSTRACT: I will critically introduce, classify and discuss the fundamental open issues related to either composite or elementary extensions of the standard model. As for the progress I will exhibit, among other things, the first proof of existence of nonsupersymmetric and non-asymptotically free 4D Gauge-Yukawa theories (structurally similar to the standard model) which are UV finite thanks to the existence of an exact interacting quantum UV fixed point in the gauge, Yukawa and scalar self-couplings. The quantum moduli space of the theory will also be precisely determined. Theories with this behaviour have been searched for on the lattice for the past several decades. Our results show the critical ingredients that are needed to construct new classes of fundamental, according to Wilson, theories featuring elementary scalars. I will then comment on the wide phenomenological impact of this discovery. |
Mar 04 2015
16:00 |
Room 005
|
Marco Taoso
(CEA - Saclay (Paris))
|
Minimal Dark Matter at colliders |
ABSTRACT: I will discuss electroweak multiplets as WIMP dark matter candidates.
In particular I will mainly focus on an EW fermion triplet, stable thanks to the accidental symmetries of the Standard Model.
I will review the relevant phenomenology for relic density calculations, direct and indirect searches. Then, I will present an analysis of the reach for such a particle at the high-luminosity LHC, and at an 100 TeV pp collider. |
Mar 02 2015
14:30 |
ICTP, Euler Room
|
Alfredo Urbano & others
()
|
|
ABSTRACT: |
Feb 18 2015
16:00 |
Room 005
|
Francesco Sannino
(CP3 - Origins)
|
Rethinking Naturalness: The Interacting Ultraviolet Safe Behaviour of Gauge-Yukawa Theories |
ABSTRACT: I will critically introduce, classify and discuss the fundamental open issues related to either composite or elementary extensions of the standard model. As for the progress I will exhibit, among other things, the first proof of existence of nonsupersymmetric and non-asymptotically free 4D Gauge-Yukawa theories (structurally similar to the standard model) which are UV finite thanks to the existence of an exact interacting quantum UV fixed point in the gauge, Yukawa and scalar self-couplings. The quantum moduli space of the theory will also be precisely determined. Theories with this behaviour have been searched for on the lattice for the past several decades. Our results show the critical ingredients that are needed to construct new classes of fundamental, according to Wilson, theories featuring elementary scalars. I will then comment on the wide phenomenological impact of this discovery. |
Feb 04 2015
16:00 |
|
Daniele Montanino
(Universit del Salento ed INFN, sez. di Lecce)
|
Neutrinos: results and perspectives |
ABSTRACT: Neutrino Physics has been one of the most exciting field of research in the last years. Through the mechanism of neutrino oscillations, neutrinos have proved to be massive and to be mixed to each other. The mass square differences and the mixing angles have been measured with high precision. However, many problems are still open: what are the absolute neutrino masses? What is the correct mass hierarchy? Do neutrinos violate CP symmetry? Are neutrino Maiorana particles (i.e. they coincide with their own antiparticles). Other puzzles open a new question: are there new sterile neutrino "states" mixed with the "active" ones? In this seminar I briefly overview the known and unknown in Neutrino Physics. |
Jan 14 2015
16:00 |
Room 128-129
|
Roberto Auzzi
(CERN - Geneve)
|
The local renormalization group equation in superspace |
ABSTRACT: |
Dec 10 2014
16:00 |
Room 005
|
Francesco Bigazzi
(INFN Pisa)
|
Holographic QCD with Dynamical Flavors |
ABSTRACT: Gravity solutions describing the Witten-Sakai-Sugimoto model of holographic QCD with dynamical flavors are presented. The field theory is studied in the Veneziano limit, at first order in the ratio of the number of flavors and colors. The gravity solutions are analytic and dual to the field theory either in the confined, low temperature phase or in the deconfined, high temperature phase with small baryonic charge density. The phase diagram and the flavor contributions to vacuum (e.g. string tension and hadron masses) and thermodynamical properties of the dual field theory are then deduced. The phase diagram of the model at finite temperature and imaginary chemical potential, as well as that of the unflavored theory at finite theta angle are also discussed in turn, showing qualitative similarities with recent lattice studies. Interesting degrees of freedom in each phase are discussed. |
Dec 03 2014
16:00 |
Room 005
|
Marco Bochicchio
(Univ. Rome)
|
An asymptotic solution of large-N QCD, and of large-N n=1 SUSY YM |
ABSTRACT: |
Dec 01 2014
14:30 |
ICTP Euler Lecture Room
|
Jacobo Lopez Pavon & others
()
|
|
ABSTRACT: |
Nov 19 2014
16:00 |
Room 005
|
Luca Merlo
(UAM and IFT)
|
Higgs particle: elementary or not? |
ABSTRACT: With the discovery of a scalar resonance at ATLAS and CMS, the understanding of the electroweak symmetry breaking origin seems a much closer goal. Deviations from SM couplings are different for theories of new physics based on a non-linear realisation of the SU(2)xU(1) gauge symmetry breaking and those assuming a linear realisation. I will review and compare the effective Lagrangians of the linear and non-linear realisations and discuss some phenomenological signals. |
Jul 30 2014
16:00 |
Room 005
|
Kai Schmitz
(IPMU, Tokyo)
|
Dynamical Fractional Chaotic Inflation |
ABSTRACT: In view of the recent BICEP2 data, chaotic inflation based on a simple monomial potential, V(phi) ~ |phi|^p, is certainly among the most attractive inflationary models capable of generating a sizeable tensor-to-scalar ratio r. Here, ordinary perturbative QFT, however, only admits positive integer values for the power p. In order to obtain fractional values, such as p = 2/3 or p = 2/5, one conventionally has to rely on the mechanism of axion monodromy in string theory. As I will demonstrate in this talk, this is not necessarily so. In fact, in strongly interacting supersymmetric gauge theories, it turns out to be possible to dynamically generate inflation potentials featuring almost arbitrary fractional powers via the effect of dimensional transmutation. This opens up the intriguing possibility that inflation is nothing but a mere consequence of strong dynamics around the scale of grand unification. A very precise determination of the inflationary CMB observables would then directly allow to pinpoint the gauge structure of the inflaton sector. |
Jul 09 2014
16:00 |
Room 005
|
Yue Zhao
(SLAC and Stanford)
|
TBA |
ABSTRACT: |
Jul 09 2014
16:00 |
Room 005
|
Yue Zhao
(Stanford)
|
A Parametrically Enhanced Hidden Photon Search |
ABSTRACT: Many theories beyond the Standard Model contain hidden photons. A light hidden photon will generically couple to the Standard Model through a kinetic mixing term, giving a powerful avenue for detection using "Light-Shining-Through-A-Wall"-type transmission experiments with resonant cavities. All previous theoretical and experimental work made use only of the transverse modes of the hidden photon. We demonstrate that, with an appropriately designed experimental geometry, transmission of the longitudinal mode of the hidden photon is parametrically enhanced over transmission of the transverse modes. This significantly improves such experiments. We present a general method for calculating the expected signal, extending the previous literature to include the longitudinal mode. While optical experiments such as ALPS are unable to take useful advantage of this enhancement, the reach of existing microwave cavity experiments such as CROWS is significantly enhanced beyond their published results. Future microwave cavity experiments may be designed with an appropriate geometry to take full advantage of the longitudinal mode. This would allow a powerful probe of unexplored hidden photon parameter space, many orders of magnitude beyond current limits, including significant regions where the hidden photon can be dark matter. |
Jun 18 2014
16:00 |
Room 128-129
|
Robert Foot
(Melbourne U.)
|
How mirror dark matter might explain early Universe cosmology, galaxy structure, and direct detection experiments |
ABSTRACT: Mirror dark matter is a very special type of dark matter candidate motivated by particle physics. Mirror dark matter has both dissipative and non-dissipative self interactions, leading to non-trivial halo dynamics. It is argued that such halo dynamics can explain the properties of dark matter on galaxy scales which have been inferred from observations. Implications for cosmology and direct detection experiments are also discussed. |
Jun 11 2014
16:00 |
Room 005
|
Borut Bajc
(JSI, Ljubljana)
|
E6: the ultimate GUT |
ABSTRACT: In spite of being around for almost as long as SU(5) and SO(10), the E6 grand unified theory is much less studied. In this seminar I will review what is known about it, and propose a complete and realistic renormalizable supersymmetric theory. I will motivate why it is a candidate for being the minimal E6 model, and speculate on possible alternatives. |
May 28 2014
14:00 |
Room 005
|
Gabriele Veneziano
(CERN)
|
Ultra-high-energy gravitational scattering: where do we stand? |
ABSTRACT: I will give an overview on what we have learned so far on the S-matrix for the ultra-high-energy gravitational scattering of particles, strings, and branes. I will then compare the results to classical expectations and mention the problems that still need to be solved in order to arrive at an information-preserving description of gravitational collapse. |
May 07 2014
16:00 |
Room 005
|
Pietro Slavich
(Paris, LPTHE)
|
Split SUSY and the Higgs after LHC8 |
ABSTRACT: I will review how the findings (and lack thereof) of the first run of the LHC experiments encourage us to consider "unnatural" SUSY scenarios with heavy scalars. In particular, I will present a "Fake Split SUSY" scenario descended from a non-minimal SUSY model with Dirac gaugino masses, and I will discuss how the phenomenology of this scenario differs from the one of conventional Split SUSY. |
Apr 30 2014
16:00 |
Room - 005
|
Adam Falkowski
(LPT, Orsay)
|
Exotic Higgs Decays |
ABSTRACT: I will discuss the possibility of the LHC observing Higgs decays that are not predicted within the Standard Model. I will describe some models where the branching fraction for exotic Higgs decays can be significant without violating any existing experimental constraints. The main focus will be on the sensitivity of the 4-lepton final state to exotic Higgs decays. I will show that the current ATLAS and CMS 4-lepton data already probe a non-trivial parameter space of certain new physics scenarios, and discuss the discovery reach in the coming LHC run. |
Apr 23 2014
16:00 |
Room 005
|
Sacha Davidson
(IPN, Lyon)
|
Axions, WIMPs and Red Herrings |
ABSTRACT: The axion is a pseudo-goldstone boson, originally introduced to solve the strong CP problem of QCD. Despite its mass of order m_nu, it can contribute to cold dark matter, due to non-thermal production mechanisms in the early Universe. Axions grow Large Scale Structure in the linear regime like WIMPs, but could behave differently during non-linear
structure formation. I will touch upon some scenarios and results from the literature about galactic halos made of axions, and argue that the issue of axion Bose Einstein condensation is a red herring. |
Apr 16 2014
16:00 |
SISSA - Room 005
|
Carlo Meneghelli
(DESY)
|
Mayer-Cluster Expansion of Instanton Partition Functions and Thermodynamic Bethe Ansatz |
ABSTRACT: In arXiv:0908.4052, Nekrasov and Shatashvili pointed out that the N=2 instanton partition function in a special limit of the Omega-deformation parameters is characterized by certain thermodynamic Bethe ansatz (TBA) like equations.In this talk I will present an explicit derivation of this fact as well as generalizations to quiver gauge theories. The TBA equations derived entirely within gauge theory have been proposed to encode the spectrum of a large class of quantum integrable systems. I will conclude with some remarks on this correspondence. |
Apr 11 2014
14:00 |
Room 137
|
Aaron Vincent
(Valencia U., IFIC)
|
Solar dark matter: beyond standard models |
ABSTRACT: In this talk I will discuss the effect of non-standard DM-SM couplings on the search for dark matter using the Sun. The DM-SM cross-section is typically taken to be a constant; however, they generically depend on the kinematic quantities s, t and u, which in the non-relativistic limit can be seen as the relative DM-nucleus velocity v_rel and the transferred momentum q (or recoil energy E_R). Depending on the operator, these terms can dominate and lead to vastly different phenomenology, and can even help reconcile conflicting direct detection results. After introducing these interactions, I will describe the effect of dark matter in the Sun, and show that the parameter space explored in such studies is in many ways complementary to earth-based experiments. I will show that heat conduction by DM trapped in the sun can have a non-negligible impact on solar structure, giving us new ways of measuring the parameters of the dark sector. I will conclude with a discussion of the Solar Composition Problem, and how dark matter is a prime candidate to resolve this outstanding issue and how, for the second time in half a century, a great puzzle in solar astronomy may lead to the discovery of new physics beyond the standard model. |
Apr 02 2014
16:00 |
SISSA - Room 005
|
Jamie Tattersall
(University of Heidelberg)
|
CheckMATE: Confronting your Favourite New Physics Model with LHC Data |
ABSTRACT: In the first three years of running, the LHC has delivered a wealth of new data that is now being analysed. With over 20 fb−1 of integrated luminosity, both ATLAS and CMS have performed many searches for new physics that theorists are eager to test their model against. However, tuning the detector simulations, understanding the particular analysis details and interpreting the results can be a tedious task. I will present the CheckMATE (Check Models At Terascale Energies) program package that accepts simulated event files in many formats for any new physics model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future. |
Mar 19 2014
16:00 |
Room 005
|
Kalliopi Petraki
(NIKHEF, Amsterdam)
|
Self-interacting and asymmetric dark matter |
ABSTRACT: Observations of the galactic and subgalactic structure of our universe support a shift from the collisionless cold dark matter paradigm. Dark matter with sizeable self-interactions offers a compelling explanation of these observations. Particle-physics models of self-interacting dark matter can be well accommodated within the asymmetric dark matter scenario. Asymmetric dark matter hypothesises that the relic dark matter abundance is due to an excess of dark particles over antiparticles, and allows for sizeable and direct couplings of dark matter to light mediators. In addition, the dark particle-antiparticle asymmetry may be related to the baryon asymmetry of the universe, thus offering a dynamical explanation for the similarity of the dark and the ordinary matter abundances. Exploring the low-energy phenomenology of self-interacting asymmetric dark matter, including the effect on the dynamics of dark matter haloes, presupposes understanding the cosmology of these models, which can be quite involved. I will discuss the above, and illustrate them in the context of the atomic dark matter model. |
Mar 12 2014
16:00 |
SISSA - Room 005
|
Satoshi Nawata
(Nikhef, Amsterdam)
|
Refined Chern-Simons theory, knot homology and gauge theories |
ABSTRACT: Recently there has been a lot of progress in understanding the structure of knot homology and its relation to topological strings and gauge theories. In this talk, I will focus on refined Chern-Simons theory and its relation to 4d and 3d gauge theories. Refined Chern-Simons theory provides a way to compute HOMFLY homology of torus knots colored by symmetric representations. Via the geometric transition/engineering, these homological invariants admit interpretations as the 4d U(1) Nekrasov partition functions in the presence of a surface operator associated to knots. In addition, 3d/3d correspondence provides a way to regard these invariants as partition functions of 3d N=2 gauge theory. A hand-written note can be found in my website (https://sites.google.com/site/snawata/talks). |
Feb 19 2014
16:00 |
SISSA - Room 005
|
Filipe R. Joaquim
(CFTP, IST, Universidade de Lisboa)
|
LFV after LHC12, MEG13 and theta_13 |
ABSTRACT: In the last years there has been a lot of activity in seeking for possible relations between the physics responsible for neutrino mass generation and potential lepton flavour violating effects in charged-lepton decays. In this seminar I will discuss some issues related with charged lepton flavour violation (cLFV) in the context of the seesaw mechanism(s), and present some constraints on the parameter space taking into account the latest data coming from neutrino oscillation experiments, from the LHC and from experiments searching for cLFV decays (MEG, B-factories,). |
Feb 05 2014
16:00 |
SISSA - Room 137
|
Andrea Wulzer
(University of Padova)
|
An Equivalent Gauge and the Equivalence Theorem |
ABSTRACT: I describe a covariant formulation of massive gauge theories in which the longitudinal polarization vectors do not grow with the energy so that the energy and coupling power-counting is completely transparent at the level of individual Feynman diagrams, with obvious advantages both at the conceptual and practical level.
Since power-counting is transparent, the high-energy limit of the amplitudes involving longitudinal particles is immediately taken, and the Equivalence Theorem is easily demonstrated at all orders in perturbation theory. Since the formalism makes the Equivalence Theorem self-evident, and because it is based on a suitable choice of the gauge, we can call it an ``Equivalent Gauge''. |
Jan 22 2014
16:00 |
SISSA - Room 005
|
Isabella Masina
(Universita di Ferrara and INFN)
|
Possible Implications of the Observed Value of the Higgs Boson Mass |
ABSTRACT: I will discuss the issue of the stability of the electroweak vacuum in the Standard Model and its minimal extension including neutrinos. The recent measurement of the Higgs boson mass indeed allows to extrapolate the Higgs potential up to high energies. Possible applications to Higgs inflation models will be also discussed. |
Dec 04 2013
14:30 |
SISSA - Room 5
|
SISSA Postdocs
(SISSA)
|
Postdoc Day - 14:30-17:30 |
ABSTRACT: |
Nov 27 2013
16:00 |
SISSA - Room 005
|
Alejandro Ibarra
(TU Munich)
|
Searching for spectral features in the gamma-ray sky |
ABSTRACT: TBA |
Nov 21 2013
14:00 |
SISSA - Room 135
|
Jernej Kamenik
(Univ. Ljubljana)
|
Dark side of Higgs boson |
ABSTRACT: I will discuss the impact of hypothetical new neutral light particles on the tiny width of a light Higgs boson. To this end, I will review the possible signatures in the Higgs decay modes with missing energy, including all the relevant effective interactions, whether renormalizable or not. This includes the fully invisible Higgs boson decay, as well as modes with SM gauge bosons or fermions in the final state. In many cases, simply preventing these modes from being dominant suffices to set tight model-independent constraints on the masses and couplings of the new light states. Then I will apply this analysis to Higgs portal models of dark matter (DM), where DM is light enough to contribute to invisible Higgs decays. I will show that DM can be a thermal relic only if there are additional light particles present with masses below a few 100 GeV. Three concrete examples of viable Higgs portal models of light DM will be presented where the invisible Higgs decay constraint is not too restrictive, because it is governed by different parameters than the relic abundance. Implications of additional light particles for flavor violation and collider searches will be briefly discussed. |
Sep 17 2013
14:15 |
SISSA - Room 005
|
Clay Cordova
(Harvard U.)
|
Line Defects in N=2 QFT |
ABSTRACT: |
Sep 04 2013
16:00 |
SISSA - Room 137 (unusual room)
|
Shigeki Matsumoto
(IPMU)
|
Pure Gravity Mediation Model and its phenomenology |
ABSTRACT: Recent results of the LHC (at Higgs and BSM searches) may indicate that the SUSY scale is much heavier than expected before. The Pure Gravity Mediation Model (PGM) is one of SUSY breaking models which realizes such a high-scale SUSY scenario within the simplest setup. In the high-scale SUSY scenario, the most important question is how we can test the model or what kind of experiments can rule out the model. A key particle is the wino, which is nothing but the dark matter candidate in the model, so that phenomenology of the wino dark matter is very important to answer the above question. After introducing the PGM model, I therefore discuss some phonologies of the wino dark matter, namely, collider (LHC) signals, direct detection signal, and indirect detection signals (using gamma-rays) of the wino dark matter. |
Aug 21 2013
16:00 |
005 - SISSA
|
Mu-In Park
(Kunsan National U.)
|
Chern-Simons Theory, Virasoro Algebra, and Black Hole Entropy |
ABSTRACT: |
Jul 31 2013
16:00 |
005 - SISSA
|
O-Kab Kwon
(Sungkyunkwan U., Ewha Womans U)
|
On the gravity dual of the mass-deformed ABJM theory |
ABSTRACT: I will explain about the construction of ${cal N}=2,4$ supersymmetric abelian projections of the ${cal N}=6$ mass-deformed ABJM theory. There are well-defined dual background geometries for the ${cal N}=2$ abelian theory, while those geometries are unclear for the ${cal N}=4$ abelian theory. After I explain the basic properties of the abelian projected ABJM theory, I will talk about the gravity dual property of the vacua of the mass-deformed ABJM theory which are proven to have one-to-one correspondence with the ${mathbb Z}_k$ quotient of Lin-Lunin-Maldacena geometries. One special vacuum of the mass-deformed ABJM theory is weakly curved at every point of the entire space transverse to the M2-branes in the large $N$ limit. Based on this property I will discuss about the dual gravity of the mass-deformed ABJM theory. |
Jul 10 2013
16:00 |
005 - SISSA
|
Marco Bochicchio
(INFN-Rome, SNS-Pisa)
|
Glueball and meson propagators of any spin in large N QCD |
ABSTRACT: We prove an asymptotic structure theorem for glueball and meson propagators of any spin in large-N QCD and in n-=1 SUSY QCD with massless quarks,
that determines asymptotically the residues of the poles of the propagators in terms of their anomalous dimensions and of the spectral density of the masses.
The asymptotic theorem follows by the severe constraints on the propagators in large-N QCD with massless quarks, or in any large-N confining asymptotically-free
gauge theory massless in perturbation theory, that arise by perturbation theory in conjunction with the renormalization group and by the OPE on the ultraviolet side.
The asymptotic theorem is inspired by a recently proposed Topological Field Theory (TFT) underlying large-N pure YM, that computes sums of the scalar and of the
pseudoscalar correlators satisfying the asymptotic theorem and that implies for the large-N joint scalar and pseudoscalar glueball spectrum exact linearity in the masses squared.
On the infrared side we test the prediction of the exact linearity in the TFT by Meyer-Teper lattice numerical computation of the masses of the low-lying glueballs in SU(8) YM,
finding accurate agreement.
Besides, we employ the aforementioned ultraviolet and infrared constraints in order to compare critically the scalar or pseudoscalar glueball propagators computed
in the framework of the AdS String/large-N Gauge Theory correspondence with those of the TFT underlying large-N YM.
We find that only the TFT satisfies the ultraviolet and infrared constraints. |
May 29 2013
16:00 |
137 - SISSA
|
Kazunobu Maruyoshi
(Caltech)
|
N=1 Dynamics with T_N SCFTs |
ABSTRACT: |
May 22 2013
16:00 |
SISSA - Room 005
|
Elli Pomoni
(DESY)
|
Integrability beyond the N=4 paradigm |
ABSTRACT: N = 2 SuperConformal QCD (SCQCD) is perhaps the simplest theory outside the N = 4 "universality class" that we can attempt to study holographically.
N = 2 SCQCD is continuously connected to the N = 4 class by an interpolating family of N = 2 SCFT. We present the study of spin chains, the complete one-loop Hamiltonian and higher-loop results. We then to ask the question of integrability. We explain why a closed SU(2,1|2) sector, which exists in any N= 2 superconformal gauge theory, should be integrable to all loops. |
Apr 24 2013
16:00 |
SISSA - Room 005
|
Jose Juknevich
(Weizmann Institute, Rehovot)
|
Top Tagging at the LHC |
ABSTRACT: Top tagging is a recent approach to identifying boosted hadronic top quarks. In this talk I will summarize some of those techniques and present some of my contributions to the development of a top tagger and their different applications to searches for t bar{t} resonances. |
Apr 10 2013
9:45 |
SISSA - Room 128/129
|
Julien Lesgourgues
(CERN/Lausanne)
|
Neutrino Cosmology: status after Planck (Combined APP/TPP seminar, unusual time and location) |
ABSTRACT: Neutrino physics illustrates beautifully the interplay between cosmology and particle physics. I will review the most plausible impacts of neutrinos (active and eventually sterile) on cosmological observables, and especially on CMB anisotropies and on the large scale structure of the universe. I will discuss the implications of the recent Planck results for neutrino physics, and show what can be expected from future experiments. |
Mar 27 2013
16:00 |
SISSA - Room 005
|
Kostas Skenderis
(Universiteit van Amsterdam)
|
A holographic view of the very early universe |
ABSTRACT: In this talk I will give an overview of holographic cosmology. I will
first discuss standard inflation, show that it is holographic and
discuss the new insights that come from this. I will then present new
holographic models that describe a universe that was
non-geometric at early times and describe the phenomenology and the
observational signatures of these models. |
Mar 20 2013
16:00 |
SISSA Room 128/129 (Unusual Room)
|
Carlo Rovelli
(Marseille)
|
(Combined APP/TPP seminar) |
ABSTRACT: |
Mar 06 2013
16:00 |
SISSA - Room 005
|
Jun-Bao Wu
(Chinese Academy of Sciences)
|
Integrability of Marginally Deformed ABJM Theories |
ABSTRACT: We study the anomalous dimensions for operators in the scalar sector of beta-deformed ABJ(M) theories. We show that the anomalous dimension matrix at two-loop order gives an integrable Hamiltonian acting on an alternating SU(4) spin chain with the spins at odd lattice sides in the fundamental representation and the spins at even lattices in the anti-fundamental representation. We get a set of beta-deformed Bethe ansatz equations which give the eigenvalues of Hamiltonian of this deformed spin chain system. Based on our computations, we also extend our study to non-supersymmetric three-parameter gamma-deformation of ABJ(M) theories and find that the corresponding Hamiltonian is the same as the one in beta-deformed case at two-loop level in the scalar sector. This talk is based on joint work with Song He. |
Feb 27 2013
16:00 |
SISSA - Room 005
|
Francesco Riva
(IFAE Barcelona)
|
Has Supersymmetry been discovered on the 4th of July? |
ABSTRACT: Recent LHC searches have provided strong evidence for the Higgs, a boson whose gauge quantum numbers coincide with those of a SM fermion, the neutrino. This raises the question of whether Higgs and neutrino can be related by supersymmetry. I will show explicitly the implications of models where the Higgs is the sneutrino: from a theoretical point of view an R-symmetry, acting as lepton number is necessary; on the experimental side, squarks exhibit novel decays into quarks and leptons, allowing to differentiate these scenarios from the ordinary MSSM. |
Jan 30 2013
16:00 |
SISSA - Room 005
|
David Straub
(Mainz)
|
Indirect constraints on composite Higgs models |
ABSTRACT: The discovery of a Higgs-like scalar particle with a mass of 125 GeV has reinforced the need to address the gauge hierarchy problem: in the absence of supersymmetry, a fundamental scalar particle would require an unnatural amount of fine-tuning. This problem can be solved if the Higgs is a composite particle of a new strong interaction, in particular if it arises as a pseudo Nambu-Goldstone boson. But even then, a moderate degree of fine-tuning calls for relatively light
fermionic resonances. Apart from direct searches for such resonances, such models are strongly constrained by electroweak precision observables and flavour physics. I will present an overview of electroweak, flavour and collider constraints on composite Higgs models, considering several choices for the electroweak representations, comparing flavour-symmetric models to flavour-anarchic ones and identifying the least fine-tuned cases and their prospects. |
Jan 23 2013
16:00 |
SISSA - Room 005
|
Lorenzo Calibbi
(Brussels)
|
Phenomenology of SUSY with intermediate scales |
ABSTRACT: The presence of new matter fields charged under the
Standard Model gauge group at intermediate scales below the Grand Unification scale modifies the renormalization group evolution of the gauge couplings. This can in turn significantly change the running of the Minimal Supersymmetric Standard Model parameters, in particular the gauging and the scalar masses. As a consequence of the modified running, the low energy spectrum can be strongly affected with observable phenomenological consequences. In particular, the parameter space with neutralino Dark Matter compatible with cosmological observations
get drastically modified. Moreover, I will discuss some observables that can be used to test the intermediate scale physics at the LHC in
a wide class of models. |
Jan 16 2013
15:00 |
SISSA - Room 005
|
Simone Giacomelli
(Scuola Normale Superiore (SNS))
|
Singular points and confinement in SQCD |
ABSTRACT: In this talk I will revisit the study of singular points in N=2 SQCD with classical gauge groups. Generalizing a technique proposed recently by Gaiotto, Seiberg and Tachikawa we find that the low- energy physics at the maximally singular points involves two superconformal sectors coupled to an infrared free SU(2) gauge group. Some of these points play a key role in understanding the properties of the theory when one softly breaks extended supersymmetry to N =1, adding a mass term for the chiral multiplet in the adjoint representation. I will discuss how confinement and chiral symmetry breaking are realized in these models. |
Dec 19 2012
16:00 |
SISSA - Room 005
|
Eung Jin Chun
(KIAS)
|
LHC phenomenology of type II seesaw |
ABSTRACT: The type II seesaw mechanism introduces a Higgs triplet to explain
the observed neutrino masses and mixing. As a result, the model predicts
a peculiar signature of a doubly charged Higgs boson decaying to di-leptons
which is one of the interesting search channels at the LHC as it can tell us about
the neutrino mass pattern.
In this talk, I will discuss some of the recent developments in the field
including the latest CMS result, a novel same-sign tetra-lepton signal
coming from the triplet-antitriplet oscillation, and modifications to the standard
Higgs properties induced by the presence of the Higgs triplet. |
Nov 28 2012
16:00 |
SISSA - Room 005
|
Silvia Pascoli
(IPPP Durham)
|
Neutrino masses and mixing: from the present status to future quests |
ABSTRACT: In the past fifteen years a series of experiments has confirmed that neutrinos can oscillate between different flavors, implying that they have mass and mix. These results play a crucial role in our understanding of particle physics as they are the first solid evidence for physics beyond the Standard Model, with profound implications for the Universe and the laws which govern it.
We have just entered the precision era of neutrino physics in which crucial neutrino properties will be determined with great accuracy. In 2012 the last of the mixing angles to be measured, theta13, was discovered at reactor neutrino oscillation experiments with important consequences for the future searches of the neutrino mass hierarchy, CP-violation and deviations from the standard 3-neutrino mixing scenario.
I will review the experimental results which indicate the existence of neutrino oscillations, their implications for our understanding of neutrino properties and the questions which we have to address in the coming future. I will give an overview of the exciting experimental program which is underway and how it will potentially answer the questions about the neutrino nature, their masses and mixing. |
Nov 21 2012
16:00 |
SISSA - Room 005
|
Mark Goodsell
(Ecole Polytechnique, Paris)
|
The Higgs in Dirac gaugino models |
ABSTRACT: I will discuss the latest developments in the phenomenology of the minimal Dirac gaugino extension of the Standard Model/(N)MSSM, paying particular attention to the Higgs production and branching ratios. Such models have many advantages over their Majorana counterparts, such as increased naturalness and new couplings that can enhance the Higgs mass. The spectrum-generator-generator SARAH has been updated to include Dirac gaugino masses, which now allows the full one-loop phenomenology of the models to be studied, of which the work I shall discuss is a first step. |
Nov 14 2012
14:30 |
SISSA - Room 005
|
Jacopo Lopez-Pavon
(SISSA)
|
Can heavy neutrinos dominate neutrinoless double beta decay? |
ABSTRACT: Neutrinoless double beta decay is the key experiment in order to understand whether neutrinos are Majorana or Dirac particles. We will review the role played by the extra states associated to the seesaw models in this process, focusing on the correlation among the different contributions. In particular, we will show why the contribution due to the exchange of heavy particles is generally subdominant. An interesting exception, which arises when the light neutrino contribution cancels out, will also be studied paying special attention to the relevant one-loop effects. |
Nov 14 2012
14:50 |
SISSA - Room 005
|
Benedict von Harling
(SISSA)
|
The Scale-Invariant NMSSM and the 125 GeV Higgs boson |
ABSTRACT: The recent LHC discovery of a 125 GeV Higgs-like state suggests that the minimal supersymmetric standard model must be modified in order to preserve naturalness. A simple extension is to include a singlet superfield and consider the scale-invariant NMSSM, whose renormalizable superpotential terms contain no dimensionful parameters. This extension not only solves the -problem, but can easily accommodate a 125 GeV Higgs boson. We study the naturalness of the scale-invariant NMSSM and show that TeV scale stop masses are still allowed in much of the parameter space with 5% tuning, a 20 TeV messenger scale and singlet-Higgs couplings lambda around one. For larger values of the singlet-Higgs coupling, which relieves the electroweak VEV tuning, an additional tuning in the Higgs mass limits increasing the (lightest) stop mass beyond 2 TeV. |
Nov 14 2012
15:10 |
SISSA - Room 005
|
Wei Xue
(SISSA)
|
An optimistic CoGeNT analysis |
ABSTRACT: In this talk, I will briefly review dark matter direct detection.
Inspired by a recently proposed model of millicharged atomic dark matter (MADM), we analyze several classes of light dark matter models with respect to CoGeNT modulated and unmodulated data, and constraints from CDMS, XENON10 and XENON100. After removing the surface contaminated events from the original CoGeNT data set, we find an acceptable fit to all these data, using somewhat relaxed assumptions about the response of the null experiments at low recoil energies. We compare the fits of MADM---an example of inelastic magnetic dark matter---to those of standard elastically and inelastically scattering light WIMPs (eDM and iDM). The iDM model gives the best fit, with MADM close behind. The dark matter interpretation of the DAMA annual modulation cannot be made compatible with these results however. We find that the inclusion of a tidal debris component in the dark matter phase space distribution improves the fits or helps to relieve tension with XENON constraints. |
Nov 14 2012
15:30 |
SISSA - Room 005
|
Alfredo Leonardo Urbano
(SISSA)
|
Top asymmetries, Higgs boson and new Dark Matter signals at LHC |
ABSTRACT: We present the status of some work in progress. In particular i) a possible connection between the top asymmetries and the radiative electroweak Higgs decays and ii) new Dark Matter signals at LHC through vector boson fusion processes will be discussed. |
Nov 14 2012
16:10 |
SISSA - Room 005
|
Marja Hanussek
(SISSA)
|
Neutrino masses and LHC constraints in R-parity violating supersymmetric models & light stops at the LHC |
ABSTRACT: I will discuss how phenomenologically viable neutrino masses can be obtained in a Lepton-number violating supersymmetric model while taking into account constraints from recent LHC results, most importantly from multi-lepton and Higgs searches. Furthermore I will shortly discuss the discovery potential of light stop scenarios at the 14TeV LHC and outline how these results may be used in order to reconstruct the superpotential coupling $tilde t_1 - chi_1^pm - b$. |
Nov 14 2012
16:30 |
SISSA - Room 005
|
Can Kozcaz
(SISSA)
|
The Refinement of the Topological Strings |
ABSTRACT: The recent advances in N=2 SUSY theories motivated the refinement of the topological string theory. One of the direct methods to compute the refined topological string partition function is the refined topological vertex. In this talk, the refined vertex will be introduced and some applications will be discussed. |
Nov 14 2012
16:50 |
SISSA - Room 005
|
Michele Pinamonti
(SISSA)
|
Search for ttbar + Higgs events at ATLAS (LHC) |
ABSTRACT: ATLAS and CMS experiments recently discovered a new particle decaying into gamma-gamma and Z-Z, compatible with the Standard Model Higgs boson with a mass around 125 GeV. Searches for the same particle in less important decay and production channels are therefore becoming more and more important to establish the couplings (and consequently the nature) of the new Higgs-like particle. The observation of the ttH(->bb) channel, where the Higgs is produced in association with a pair of top quarks and decays to a pair of bottom quarks, would offer the possibility to isolate purely fermionic Higgs couplings. The large\r\namount proton-proton collision data collected by the ATLAS experiment during the past two years at the centre-of-mass energies of 7 and 8 TeV at the LHC, the excellent performances of the detector and the sophisticated analysis techniques will hopefully allow to see and measure this challenging process. |
Oct 03 2012
16:00 |
SISSA - Room 005
|
Enrico Bertuzzo
(IPhT- CEA Saclay)
|
Do h->gamma gamma and gluon gluon -> h taste like vanilla new physics? |
ABSTRACT: After an introduction on the current experimental status of the Higgs boson, I will study the effect of new vector-like fermions on the gluon gluon -> h and h -> gamma gamma channels, in which the effect of new physics may be already showing up. In particular, I will analyze fermions in their smallest SU(2) representations, and the modifications to the previously mentioned channels in regions allowed by electroweak precision measurements. |
Sep 26 2012
16:00 |
SISSA
|
Marco Nardecchia
(CP3 Origins)
|
On Partial Compositeness and the CP Asymmetry in Charm Decays |
ABSTRACT: Recently, the LHCb and CDF collaborations reported the measure of a direct CP asymmetry in D meson decays. In this talk we ask if new physics associated with Partial Compositeness could plausibly explain this result. The realization of Partial Compositeness is discussed in the context of the (non-suy) composite Higgs models and within supersymmetry. |
Sep 19 2012
16:00 |
SISSA - Room 005
|
Alexander Westphal
(DESY)
|
Building an explicit de Sitter |
ABSTRACT: |
Sep 05 2012
16:00 |
SISSA - Room 005
|
Junbao Wu
(Institute of High Energy Physics, Chinese Academy of Sciences)
|
Holographic Correlation Functions of Giant Gravitons |
ABSTRACT: |
Jul 06 2012
16:30 |
Euler Lecture Hall, ICTP
|
Sanved Kolekar
(IUCAA, India)
|
Some issues in horizon thermodynamics |
ABSTRACT: |
Jul 04 2012
9:00 |
Room 128
|
ATLAS and CMS spoke-persons
(CERN)
|
Update on the Standard Model Higgs searches in CMS and ATLAS |
ABSTRACT: |
Jun 27 2012
16:00 |
Lecture Hall 005
|
Chiara Caprini
(CEA - Saclay)
|
Primordial magnetic fields: initial conditions and CMB anisotropy at large scales |
ABSTRACT: Large scale magnetic fields are ubiquitous in the universe. Observations of galaxies and clusters, even at high redshift, show that microGauss magnetic fields are present in these astrophysical objects, correlated on the same scale of the object itself. Recently, a lower bound on the magnetic field amplitude in voids has been established using gamma ray telescopes. However, the origin of these magnetic fields is still unknown: understanding when and how they formed, and how they evolved after formation is one of the problem of modern cosmology. This seminar focusses on the hypothesis that the rnmagnetic fields observed today in matter structures have been rngenerated in the primordial universe, during inflation or during an instantaneous causal process, like e.g. a phase transition. The neatest way to confirm the presence of a magnetic field of primordial origin would be to observe its trace in the cosmic microwave background. I will derive the initial conditions and the evolution of the metric perturbations generated both by an inflationary and by a rncausal magnetic field, with the aim of predicting the shape of the large scale temperature anisotropy that it would induce in the cosmic microwave background. |
Jun 26 2012
16:30 |
Luigi Stasi Seminar Room, ICTP
|
Svjetlana Fajfer
(Jozef Stefan Institute, Ljubljana)
|
Light Color Scalars from Low Energy to Proton Decay |
ABSTRACT: |
Jun 25 2012
16:30 |
Luigi Stasi Seminar Room, ICTP
|
Massimo Porrati
(NYU)
|
On the Unitarity of Critical Gravity, other Higher-Derivative Theories, and High Spin Randall-Sundrum Theories |
ABSTRACT: Special limits of theories with higher time derivatives in Anti de Sitter space exhibit interesting features: they realize logarithmic representations of the conformal algebra and they possess a structure akin to gauge theory. These results can be obtained by a simple study of the scalar product of free fields. This study shows that "critical" gravity in dimension larger than 3 is non-unitary, but that the spectrum of certain other higher derivative theories, such as the Flato-Fronsdal singleton dipole theory, contains a unitary subsector. Unitarity of a high spin generalization of the Randall-Sundrum construction will be also discussed. |
Jun 21 2012
16:30 |
Euler Lecture Hall, ICTP
|
Dilip K. Ghosh
(IACS, Kolkata, India)
|
Using Jet Substructure at the LHC to Search for the Light Higgs Bosons of the CP-Violating MSSM |
ABSTRACT: |
Jun 20 2012
16:00 |
Lecture Hall 005
|
Massimo Porrati
(NYU)
|
Surprises with Interacting High Spin Particles |
ABSTRACT: In this talk, old and new no go theorems that severely constrainrnpossible interactions of massless high spin particles will be reviewed. Massive particles can interact with gauge fields and gravity, but they are often plagued by pathologies such as superluminal propagation in nontrivial backgrounds. The last part of the talk uses the example of open string theory to show that such pathologies can be avoided by an appropriate choice of non-minimal interactions. |
Jun 13 2012
16:00 |
Lecture Hall 005
|
Veronika Hubeny
(Durham University)
|
CFT probes of bulk geometry |
ABSTRACT: Motivated by the need for further insight into the emergence
of AdS bulk spacetime from CFT degrees of freedom, we explore the behaviour of probes represented by specific geometric quantities in the bulk. In particular, we study how deep into the bulk can various extremal surfaces anchored on the boundary reach, demonstrating that such surfaces cannot penetrate static black hole horizons. We then explore the properties of bulk causal wedge naturally associated with a given region on the boundary, focusing on a specific quantity which we dub the causal holographic information. |
Jun 01 2012
16:30 |
Euler Lecture Hall - ICTP
|
Cumrun Vafa
(Harvard University, Cambirdge, USA)
|
Knots and Mirrors |
ABSTRACT: |
May 25 2012
16:30 |
Euler Lecture Hall - ICTP
|
Andreas Weiler
(DESY, Hamburg)
|
Natural and flavorful SUSY at the LHC |
ABSTRACT: |
May 09 2012
16:00 |
Room 005
|
Sven Heinemeyer
(Santander )
|
LHC Searches for Higgs and SUSY from a Theory Perspective |
ABSTRACT: |
Mar 28 2012
16:00 |
Room 005
|
Wilfried Buchmueller
(DESY)
|
Spontaneous B-L Breaking as the Origin of the Hot Early Universe |
ABSTRACT: |
Feb 08 2012
16:00 |
Room 005
|
Andrea de Simone
(SISSA)
|
Electroweak light from dark matter |
ABSTRACT: The indirect searches for Dark Matter (DM) are based on
detecting excesses
in the fluxes of cosmic rays produced by DM annihilations in the galaxy. These fluxes can be significantly altered by the inclusion of electroweak gauge boson
radiation. I will discuss the situations where the effect of electroweak radiation is particularly important, and describe in more detail the cases when the DM resembles the bino or the wino of
supersymmetric models. I will also comment on the effective field theory formulation.
|
Sep 28 2011
16:00 |
SISSA, Room 004
|
Jure Zupan
(University of Cincinnati)
|
Flavor symmetries and processes with tops |
ABSTRACT: |
Jun 15 2011
16:00 |
SISSA, room 005
|
Sergey Sibiryakov
(INR, Moscow )
|
Technically natural dark energy from Lorentz breaking |
ABSTRACT: |
Jun 08 2011
16:00 |
SISSA, Room 005
|
Christophe Grojean
(CERN )
|
Alternatives to the SM Higgs boson |
ABSTRACT: |
May 18 2011
16:00 |
SISSA, room 004
|
Sabine Kraml
(LPSC, Grenoble)
|
Light mixed sneutrino dark matter |
ABSTRACT: |
May 11 2011
16:00 |
SISSA, Room 005
|
Javier Tarrio
(Utrecht University )
|
The open string membrane paradigm in AdS/CFT |
ABSTRACT: |
May 04 2011
16:00 |
SISSA, Room 005
|
Christoph Luhn
(Southampton University)
|
Non-Abelian discrete family symmetries from SU(3) |
ABSTRACT: |
Apr 20 2011
16:00 |
SISSA, room 005
|
Alessandro Vichi
(EPFL)
|
Exploring Conformal Field Theories |
ABSTRACT: |
Apr 13 2011
16:00 |
SISSA, Room 005
|
David Marsh
(Cornell University )
|
Sequestering in String Compactifications |
ABSTRACT: I will describe recent efforts to understand the mediation of supersymmetry breaking in compactifications of string theory whose moduli are stabilized by non-perturbative effects. Geometric separation between the visible and the supersymmetry breaking sectors has been argued to lead to sequestering, but I will describe how moduli stabilization effects may spoil sequestering. In some of the phenomenologically most successful models, the effects of moduli
stabilization can be significant and may induce non-negligible CP-violation and flavor changing neutral currents as well as problems for electro-weak symmetry breaking. |
Apr 06 2011
16:00 |
SISSA, Room 005
|
Bennie F. L. Ward
(Baylor University)
|
Planck Scale Cosmology and Asymptotic Safety in Resummed Quantum Gravity: An Estimate of Lambda |
ABSTRACT: In Weinberg's asymptotic safety approach to quantum gravity, a finite dimensional critical surface for a UV stable fixed point generates a theory of quantum gravity with a finite number of physical parameters. We argue that, in a recently formulated extension of Feynman's original formulation of the theory, which we have called resummed quantum gravity, we recover this fixed-point UV behavior from an exact re-arrangement of the respective perturbative series. Our the results are consistent both with the exact field space Wilsonian renormalization group results of Reuter et al. and with recent Hopf-algebraic Dyson-Schwinger renormalization theory results of Kreimer. Our first "first principles" predictions of the respective dimensionless gravitational and cosmological constants support the Planck scale cosmology advocated by Bonanno and Reuter as well. We arrive at the "first principles" estimate of the cosmological constant ρΛ ≅ (2.400 x 10-3 eV)4 |
Mar 23 2011
16:00 |
SISSA, Room 005
|
Giuseppe Policastro
(LPT Ecole Normale Superieure)
|
Optical properties of holographic relativistic plasmas |
ABSTRACT: I will discuss how the gauge/gravity holographic correspondence can be used to study the electromagnetic response and optical properties of a certain class of media, namely strongly coupled relativistic plasmas; in particular it can be shown that they exhibit the phenomenon of negative refraction in a certain range of frequencies, that is observed in artificially realized metamaterials. I will also discuss the relevance of the results for non-relativistic systems, e.g. Fermi liquids. |
Mar 16 2011
16:00 |
SISSA, Room 005
|
Roberto Contino
(Roma La Sapienza)
|
The effect of resonances in strong WW scattering |
ABSTRACT: |
Mar 09 2011
16:00 |
SISSA, Room 005
|
Umberto De Sanctis
(SISSA)
|
One year with the ATLAS experiment at LHC: measurements, limits and hopes |
ABSTRACT: In this seminar, I will review the principal measurements of the ATLAS experiment at Large Hadron Collider at CERN with the data collected in 2010. The attention will be mainly brought to the Standard Model physics and the searches for the Higgs boson, Supersymmetry and many other signatures related to different scenarios of physics "beyond the Standard Model". The prospects for 2011 will be also presented |
Mar 02 2011
16:00 |
SISSA, room 005
|
Kazuo Hosomishi
(Kyoto University)
|
AGT on the S-duality Wall |
ABSTRACT: Three-dimensional gauge theory T[G] arises on a domain wall between four-dimensional N=4 SYM theories with the gauge groups G and its S-dual GL. We argue that the N=2* mass deformation of the bulk theory induces a mass-deformation of the theory T[G] on the wall. The partition functions of the theory T[SU(2)] and its mass-deformation on the three-sphere are shown to coincide with the transformation coefficient of Liouville one-point conformal block on torus under the S-duality. |
Feb 07 2011
16:00 |
SISSA, room 005
|
Riccardo Barbieri
(SNS, Pisa)
|
Beyond the standard MSSM |
ABSTRACT: If supersymmetry is relevant at the Fermi scale, the lack of any direct signal so far may require going beyond the Minimal Supersymmetric Standard Model. I analyze a simple and concrete extension of the MSSM that takes these issues, including a way to address the flavour and the CP problems. In its fully natural range of parameters, the expected signals for LHC, dark matter and flavour physics are clear and generally quite different from the ones of the MSSM. Gauge coupling unification may be only approximate. |
Jan 26 2011
10:30 |
SISSA, Room 005
|
Diego Rodriguez-Gomez
(Technion)
|
A holographic approach to phase transitions |
ABSTRACT: Possible applications of the gauge/gravity duality to condensed matter systems have attracted a great attention over the last few years. In particular, holographic descriptions of phase transitions in strongly coupled systems have attracted much attention. Following mostly a bottom-up approach, in this talk we will study some such models which can accommodate a wide range of critical exponents, thus potentially describing a large class of systems. We will also discuss the case of p-wave condensates by focusing on a mild deformation of gauged 5d SUGRA. In fact our results can shed some light into phases of R-charged black holes. |
Jan 23 2011
16:00 |
SISSA
|
Samoil M. Bilenky
(Dubna, JINR & Munich, Tech. U.)
|
TBD |
ABSTRACT: |
Jan 19 2011
16:00 |
SISSA, Room 005
|
Michele Redi
(CERN)
|
Low Scale Flavor Gauge Symmetries |
ABSTRACT: I will discuss the possibility of gauging the Standard
Model flavor group. Anomaly cancellation leads to the addition of
fermions whose mass is inversely proportional to the known fermion
masses. In this case all flavor violating effects turn out to be
controlled roughly by the Standard Model Yukawas, suppressing
transitions for the light generations. Due to the inverted hierarchy
the scale of new flavor gauge bosons could be as low as the
electroweak scale without violating any existing bound but accessible
at the Tevatron and the LHC. The mechanism of flavor protection
potentially provides an alternative to Minimal Flavor Violation, with
flavor violating effects suppressed by hierarchy of scales rather
than couplings. |
Jan 12 2011
16:00 |
SISSA
|
Driba D. Tolla
(Sungkywnkwan University)
|
Interaction between multiple M2-branes and bulk form fields in the context of ABJM model |
ABSTRACT: |
Dec 15 2010
16:00 |
SISSA, Room 005
|
I. Amado, K. Maruyoshi, I. Smolic, M. Spinrath
(SISSA)
|
Postdoc Day |
ABSTRACT: Anomalous hydrodynamics from holography: the chiral vortical conductivity - AGT Relation, Matrix Model, and Integrable System - Black hole entropy in the presence of gravitational Chern-Simons terms - Aspects of Flavour Model Building in Supersymmetric Grand Unification |
Jul 21 2010
16:00 |
SISSA, Room 137
|
Stefano Rigolin
(University of Padua, Italy)
|
A "novel" symmetry breaking mechanism in extra dimensions |
ABSTRACT: We review the basic notions of compactification in the presence of a background flux.
In extra-dimentional models with more than five dimensions, Scherk and Schwarz boundary conditions have to satisfy 't Hooft consistency conditions.
Different vacuum configurations can be obtained, depending whether trivial or non-trivial 't Hooft flux is considered.
The presence of the "magnetic" background flux provides, in addition, a mechanism for producing four-dimensional chiral fermions.
Particularizing to the six-dimensional case, we calculate the one-loop effective potential for a U(N) gauge theory on M4 x T2.
We firstly review the well known results of the trivial 't Hooft flux case, where one-loop contributions produce the usual Hosotani dynamical symmetry breaking.
Finally we applied our result for describing, for the first time, the one-loop contributions in the non-trivial 't Hooft flux case. |
Jul 14 2010
16:00 |
SISSA, Room 137
|
Giuliano Panico
(ETH Zurich, Switzerland)
|
Mesons and Baryons from Holographic QCD |
ABSTRACT: By following an "inverse" holographic approach we construct a 5D effective theory that captures several aspects of hadron physics in the large Nc limit.
Baryons arise in this set up as calculable 5D Skyrmions.
In spite of the simplicity of the model and of the limited number of free parameters, we get a surprisingly good agreement with the experimental data for many mesonic and baryonic observables. |
May 26 2010
16:00 |
SISSA, Room 137
|
Kazunobu Maruyoshi
(Yukawa Institue, Japan)
|
Seiberg-Witten Theory via Penner Type Matrix Model |
ABSTRACT: We discuss the Penner type matrix model recently proposed by Dijkgraaf and Vafa for a possible explanation of the relation between two-dimensional CFT and Nekrasov partition function of N=2 gauge theory.
We see the spectral curve of the matrix model in planar limit correctly matches with the Seiberg-Witten curve of SU(2) quiver gauge theory.
We calculate the planar free energy of this matrix model for the simplest quiver case, that is, SU(2) gauge theory with four flavors and see the precise agreement with the gauge theory prepotential.
We also discuss the decoupling of massive flavors from the matrix model and derive matrix models describing asymptotically free N = 2 gauge theories.
(Ref: Tohru Eguchi and Kazunobu Maruyoshi, arXiv:0911.4797 [hep-th]) |
May 19 2010
16:30 |
SISSA, Room 137
|
Sebastian Cassel
(University of Oxford, UK)
|
The fine tuning guide for SUSY searches |
ABSTRACT: Low energy supersymmetry can be theoretically motivated as a solution to the hierarchy problem of the Standard Model if the superpartner states are not too heavy. The non-observation of SUSY and precision tests then introduces some tension in the attempt for naturalness. I will present a study of the amount of fine tuning at 2-loop order in the constrained MSSM and discuss which regions of the parameter space are preferred on naturalness grounds. The implications for the most promising collider and dark matter search strategies for observing SUSY will also be considered. |
May 12 2010
16:30 |
SISSA, Room 137
|
Giovanni Villadoro
(CERN)
|
Simple Z' in the early LHC |
ABSTRACT: Extra vector bosons are a common feature of many extensions of the Standard Model and represent one of the easiest smoking gun of new physics to look for. I will discuss present bounds from direct and indirect searches on the existence of extra spin-1 particles coupled to the Standard Model fields through renormalizable interactions and the possibility of an early discovery at the LHC. |
May 05 2010
16:30 |
SISSA, Room 137
|
Carlos Nuez
(Swansea University, Wales)
|
Aspects of Gauge Strings Duality |
ABSTRACT: I will discuss recent developments in the duality between gauge fields and Strings. |
Mar 17 2010
16:30 |
SISSA, Room D
|
Miguel Paulos
(DAMTP, Cambridge, UK)
|
Viscosity and conductivity in general theories of gravity |
ABSTRACT: Recently there has been great interest in calculating transport coefficients for field theories at large coupling, using AdS/CFT.
In this talk I will discuss recent work showing how to use the membrane paradigm to easily compute the shear viscosity and conductivity in arbitrary gravity theories.
In a certain sense these can be thought of as effective couplings at the black hole horizon dual to the field theory plasma. An explicit Wald-like formula for these couplings is given for a large class of generalized gravity theories. |
Mar 03 2010
16:30 |
SISSA, Room D
|
Liuba Mazzanti
(Santiago de Compostela University)
|
Holographic gluon plasma hydrodinamics from 5d Dilaton-Gravity |
ABSTRACT: |
Feb 24 2010
16:30 |
SISSA, Room D
|
Timo Weigand
(Heidelberg University, Germany)
|
Compact F-theory GUT model building |
ABSTRACT: |
Feb 17 2010
16:30 |
SISSA, Room D
|
Umberto De Sanctis
(SISSA)
|
First results with the ATLAS detector at LHC |
ABSTRACT: In this talk, I will show the performances of the ATLAS detector and the first physical results with real data collected during the final month of 2009, after the restart of LHC. The possibility to discover high mass scalar resonances, within the chiral lagrangian framework, in the Vector Boson Scattering channel will also be discussed. |
Feb 10 2010
16:30 |
SISSA, Room D
|
Alessandro Tomasiello
(University of Milano "Bicocca)
|
The gauge dual of Romans mass |
ABSTRACT: We review recent progress in constructing exact non-BPS solutions of 5D supergravity. The solutions we construct describe (multi) black holes and black rings as well as regular horinzon-less solutions with the same asymptotic charges of non-BPS black holes. |
Jan 27 2010
16:30 |
SISSA, Room D
|
Toshihiko Oto
(Max-Planck-Institut fuer Physik, Muenchen)
|
Neutrino masses from higher than dimension five effective operators |
ABSTRACT: |
Jan 26 2010
16:00 |
ICTP - Euler Lecture Hall
|
Sergio Cecotti
(SISSA)
|
Yukawa couplings in F-theory and a Quantum residue formula |
ABSTRACT: |
Jan 13 2010
16:30 |
SISSA, Room D
|
Pomita Ghoshal
(SISSA)
|
Determining the neutrino mass hierarchy via future atmospheric neutrino detectors |
ABSTRACT: The effect of the earth's matter on neutrinos passing through the earth modifies the neutrino oscillation probabilities and enhances the sensitivity to the neutrino mass hierarchy and other neutrino parameters. I will review how this happens, and how this effect can be exploited using atmospheric neutrinos in future detectors, comparing the advantages and sensitivities that can be obtained in different kinds of detectors - a magnetized iron detector, a water Cerenkov detector and a Liquid Argon detector. |
Oct 14 2009
16:30 |
SISSA, Room D
|
Bobby Acharya
(ICTP)
|
The Non-thermal WIMP Miracle and the LHC |
ABSTRACT: |
May 06 2009
16:30 |
SISSA, Room D
|
Damiano Anselmi
(Uiversit di Pisa)
|
Standard Model and High Energy Lorentz Violation |
ABSTRACT: |
Mar 18 2009
16:30 |
SISSA, Room D
|
David Tong
(DAMTP, Cambridge, UK)
|
Berry Phase and Supersymmetry |
ABSTRACT: |
Mar 04 2009
16:30 |
SISSA, Room D
|
Minoru Eto
(University of Pisa)
|
Multiple layer structures of non-Abelian vortex and interactions |
ABSTRACT: |
Feb 18 2009
16:30 |
SISSA, Room D
|
Claudia Hagedorn
(SISSA)
|
Fermion Mixings from Discrete Symmetries: The Cabibbo Angle from the Dihedral Group D_{14} |
ABSTRACT: Flavor symmetries, especially if they are broken in a particular way, seem to be the prime candidate for predicting the fermion mass and mixing patterns correctly. In this talk we present a supersymmetric model with the flavor symmetry D_{14} in which the CKM
matrix element |V_{ud}| can take the value |V_{ud}| =cos ( pi/14 ) =
0.97493. This value is very close to the one observed in experiments.
The value of |V_{ud}| is based on the fact that different Z_{2} subgroups of D_{14} are conserved in the up and down quark sector. The quark mass hierarchy is partly due to the flavor group D_{14} and partly due to a Froggatt-Nielsen symmetry U(1)_{FN}. The model is
completely natural in the sense that the hierarchies among the quark
masses and mixing angles are generated with the help of symmetries.
The vacuum alignment of the flavor symmetry breaking fields is
discussed as well as corrections stemming from the Z_{2} breaking
in the up and down quark sector. |