Theoretical Particle Physics

TPP Group Seminar History
Date	Room	Speaker	Title
Sep 17 2013 14:15	SISSA - Room 005	Clay Cordova (Harvard U.)	Line Defects in N=2 QFT
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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
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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
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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)
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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
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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
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Jul 06 2012 16:30	Euler Lecture Hall, ICTP	Sanved Kolekar (IUCAA, India)	Some issues in horizon thermodynamics
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Jul 04 2012 9:00	Room 128	ATLAS and CMS spoke-persons (CERN)	Update on the Standard Model Higgs searches in CMS and ATLAS
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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
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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
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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
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May 25 2012 16:30	Euler Lecture Hall - ICTP	Andreas Weiler (DESY, Hamburg)	Natural and flavorful SUSY at the LHC
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May 09 2012 16:00	Room 005	Sven Heinemeyer (Santander )	LHC Searches for Higgs and SUSY from a Theory Perspective
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Mar 28 2012 16:00	Room 005	Wilfried Buchmueller (DESY)	Spontaneous B-L Breaking as the Origin of the Hot Early Universe
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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
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Jun 15 2011 16:00	SISSA, room 005	Sergey Sibiryakov (INR, Moscow )	Technically natural dark energy from Lorentz breaking
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Jun 08 2011 16:00	SISSA, Room 005	Christophe Grojean (CERN )	Alternatives to the SM Higgs boson
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May 18 2011 16:00	SISSA, room 004	Sabine Kraml (LPSC, Grenoble)	Light mixed sneutrino dark matter
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May 11 2011 16:00	SISSA, Room 005	Javier Tarrio (Utrecht University )	The open string membrane paradigm in AdS/CFT
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May 04 2011 16:00	SISSA, Room 005	Christoph Luhn (Southampton University)	Non-Abelian discrete family symmetries from SU(3)
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Apr 20 2011 16:00	SISSA, room 005	Alessandro Vichi (EPFL)	Exploring Conformal Field Theories
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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 ρ_Λ ≅ (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
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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 G^L. 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
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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
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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 Nu�ez (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
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Feb 24 2010 16:30	SISSA, Room D	Timo Weigand (Heidelberg University, Germany)	Compact F-theory GUT model building
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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
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Jan 26 2010 16:00	ICTP - Euler Lecture Hall	Sergio Cecotti (SISSA)	Yukawa couplings in F-theory and a Quantum residue formula
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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
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May 06 2009 16:30	SISSA, Room D	Damiano Anselmi (Uiversit� di Pisa)	Standard Model and High Energy Lorentz Violation
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Mar 18 2009 16:30	SISSA, Room D	David Tong (DAMTP, Cambridge, UK)	Berry Phase and Supersymmetry
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Mar 04 2009 16:30	SISSA, Room D	Minoru Eto (University of Pisa)	Multiple layer structures of non-Abelian vortex and interactions
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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.