List of Talks

large N $┬ąphi^4$ model in 3-dimensions and the conformal fixed point
Aoki, Sinya (Yukawa Institute for Theoretical Physics, Kyoto University)
We investigate $┬ąphi^4$ model in 3-dimensions, by taking the large N limit. We construct 4-types of continuum field theories around two fixed points, the asymptotic free fixed pointa and the Wilson-Fischer fixed point. We calculate the beta function for the running coupling constant in each case. We futher relate the behavior of the scattering phase shift to the propertty of the beta function.
Flavor and Scalar Signals of Extended Color Sector
Chivukula, R. Sekhar (Michigan State University)
The new strong interactions of composite Higgs models are often based on an extended color sector. In this talk report on a study of such a model incorporating next-to-minimal flavor violation, update bounds coming from flavor physics, and review potential collider signals involving the top-quark and the color symmetry breaking sector.
Anomalous dimensions at an IRFP
Del Debbio, Luigi (University of Edinburgh)
The SU(2) gauge theory with two fermions in the adjoint representations is supposed to have an IR fixed point. We discuss the determination of the anomalous dimensions of the mass and the four-fermi coupling in this theory using numerical simulations.
Dynamic AdS/QCD - holography of the conformal window and walking dynamics
Evans, Nick (University of Southampton)
Dynamic AdS/QCD is a holographic model of chiral symmetry breaking in strongly coupled gauge theories, with key features from top down string constructions. The gauge dynamics is imprinted through the running of the anomalous dimension of the qbar q operator, gamma. The BF bound in AdS space inplies that chiral symmetry breaking sets in when gamma = 1. The model allows the computation of the rho, pi, sigma, and a masses plus their decay constants. In the conformal window one can study the scaling dimensions of physical quantities such as the quark condensate in the massive theory and show that they satisfy dimensional expectations (hyperscaling relations) in both the UV and IR. The model predicts their evolution in the intermediate running regime which maybe of help for lattice simulations of these theories. In the walking gauge theory regime the model displays enhancement of the quark condensate and suppression of the sigma's mass relative to the rest of the spectrum.
SU(2) with six flavors: A new kind of gauge theory
Fleming, George (Yale University)
The SU(2) Yang-Mills gauge theory with six flavors of Dirac fermions in the fundamental representation would produce a very large number of massless NG bosons if chiral symmetry is spontaneously broken. It has been conjectured that flow to an IR fixed point preserves the chiral symmetry. We present strong evidence that if such an IRFP exists, it must be very strongly coupled. Whether chiral symmetry ultimately breaks or not, in either case the resulting low energy behavior has no known analog in other Yang-Mills gauge theories.
Higgs as a Top-Mode Pseudo
Fukano, Hidenori (KMI, Nagoya University)
We propose a model which has a naturally light composite Higgs boson, ``tHiggs", to be identified with the 126 GeV Higgs discovered at the LHC in the spirit of the top quark condensation. The tHiggs emerges as a pseudo Nambu-Goldstone boson, ``Top-Mode Pseudo'', together with the exact NGBs to be absorbed into the W and Z bosons as well as another (heavier) Top-Mode Pseudo. We also discuss LHC phenomenologies of the Top-Mode Pseudos.
A UV completion of a Composite Higgs model
Gherghetta, Tony (University of Minnesota)
Anomalous mass dimension from the spectral density near the conformal window
Hasenfratz, Anna (University of Colorado Boulder)
In gauge-fermion systems the spectral density of the Dirac operator covers both the ultraviolet and infrared region as the eigenvalue changes from 0 to O(1). This unique property offers a novel way to compare chirally broken and conformal systems. We have studied several systems both below and above the conformal window using different staggered lattice actions to investigate the universality of the lattice predictions. In this talk I will focus on 12 fundamental fermions but will show results relevant to the 8 flavor system as well.
QCD under a strong magnetic field
Hong, Deog-Ki (Pusan National University)
Charged particles occupy Landau levels under a uniform external magnetic field. When the Landau gap is much bigger than the scale of QCD, lowest Landau level quarks are the relevant degrees of freedom. We derive an effective theory of QCD with quarks in the lowest Landau level to see how the chiral symmetry of QCD is broken in the strong magnetic fields. We then apply the effective theory to study the cooling of magnetars.
Holographic description of quantum black hole on a computer
Hyakutake, Yoshifumi (Ibaraki University)
The discovery of the fact that black holes radiate particles and eventually evaporate led Hawking to pose the well-known information loss paradox. This paradox caused a long and serious debate since it claims that the fundamental laws of quantum mechanics may be violated. A possible cure appeared recently from superstring theory, a consistent theory of quantum gravity: if the holographic description of a quantum black hole based on the gauge/gravity duality is correct, the information is not lost and quantum mechanics remains valid. Here we test this gauge/gravity duality on a computer at the level of quantum gravity for the first time. The black hole mass obtained by Monte Carlo simulation of the dual gauge theory reproduces precisely the quantum gravity effects in an evaporating black hole. This result opens up totally new perspectives towards quantum gravity since one can simulate quantum black holes through dual gauge theories.
The Muon g-2: present and future
Jegerlehner, Fred (DESY Zeuthen/Humboldt University Berlin)
The anomalous magnetic moment of the muon provides stringent tests for the electroweak Standard Model and is a excellent monitor for new physics. I present a summary of the status and on recent progress, emphasizing problems and possible solutions in the determination of the hadronic contributions: vacuum polarization and ligh-by-light scattering. They represent the challenge in reducing theoretical uncertainties to match the precision of forthcoming experiments, expected to go into operation within a few years from now. The impact of recent LHC results for the interpretation observed 3-4 sigma "discrepancy" in the muon g-2 is briefly discussed.
Two topics on scale invariant extensions of the SM
Ko, Pyungwon (KIAS)
In this talk, I discuss two types of scale invariant extensions of the SM. First I will describe a scale invariant model with strongly interacting hidden sector, frmo which all the mass scales including the dark matter masses are generated nonperturbative dynamics. Then I will discuss the Higgs-dialton(radion) system assuming there is a light dilaton from some scale invariant sector. Imposing a condition that the dilaton couples to the trace of energy-momentum tensor with the full gauge symmetry group of the SM, and not with its unbroken subgroup, we show that the Higgs phenomenology can be significantly different compared with earlier studies.
Technihadrons -- spectrum and collider phenomenologies
Kurachi, Masafumi (KMI, Nagoya University)
We consider the one-family technicolor model as the dynamical origin of the electroweak symmetry breaking. As low-energy degrees of freedom, we consider Techni-Pions (associated with the spontaneous breaking of global symmetry), Techni-Dilaton (which is identified as the 126 GeV scalar discovered at the LHC) as well as Techni-Rho mesons as typical resonances expected to appear in such model. We first discuss the mass spectrum of technihadrons based on the holographic calculations. Then the effective Lagrangian is constructed based on the formulation of the Hidden Local Symmetry, and we discuss implications for collider phenomenology based on that Lagrangian.
Higgs impostor, or just a light scalar on the lattice?
Kuti, Julius (University of California, San Diego)
The minimal realization of a light scalar state with Higgs quantum numbers in near-conformal strongly coupled gauge theories will be discussed. The identification of the composite light scalar with the Higgs impostor would have to overcome serious conceptual and practical challenges in the lattice based approach.
Running coupling of SU(3) gauge theory with 12 flavours in a twisted box
Lin, C.-J. David (National Chiao-Tung University, Taiwan)
We present our work on the running coupling of SU(3) gauge theory with 12 flavours in a twisted box. The beta function of this theory is known to be very small. This implies the need for high-precision calculations in determining whether there is an infrared fixed point in this theory. In this talk, we discuss the features of our work in achieving a high-accuracy computation of the renormalised coupling constant.
How many scales in many-flavor QCD?
Lombardo, Maria Paola (INFN)
We discuss our lattice results obtained in QCD for a number of light flavors ranging from zero to twelve. Our analysis supports a scenario in which different physical scales appear in QCD when approaching the conformal window, give hints on the position and nature of the singularity itself, and on the value of the theory's anomalous dimension.
Technidilaton in light of LHC-Run II
Matsuzaki, Shinya (Nagoya University)
The LHC scalar boson at 125 GeV can be identified as the technidilaton, pseudo Nambu-Goldstone boson for the spontaneous breaking of scale symmetry in walking technicolor. The precise estimate of the couplings to the standard model particles, set by the dilaton decay constant, will be crucial at the upcoming LHC-Run II to tell the standard Higgs from the technidilaton. It is actually doable at lattices, by examining the chiral extrapolation of the dilaton mass against the technipion mass. This talk will summarize the technidilaton phenomenology in comparison with the currently available LHC data, and introduce a way of simultaneous determination of the dilaton decay constant and mass at lattices.
Relativistic matter in a magnetic field: a new face of the chiral anomaly
Miransky, Vladimir (Western University, Canada, and KMI)
Collisions between heavy nuclei at RHIC collider produce some of the strongest magnetic fields that can be generated under laboratory conditions. The recent experiments indicate the existence of P, CP, and time reversal violation effects in hot relativistic matter produced at RHIC. Theoretical works suggested that these effects are generated by a strong QCD dynamics in relativistic matter in a magnetic field. It has been recently argued that this dynamics is intimately connected with some new features of the chiral anomaly. I will describe these features and the latest results in their experimental studies.
Walking Signals of N_f=8 QCD
Nagai, Kei-ichi (KMI, Nagoya University)
We investigate walking signals of $N_f=8$ QCD through meson spectrum using the HISQ action. Our data for the $N_f=8$ QCD are consistent with the spontaneously broken chiral symmetry in the chiral limit extrapolation of the chiral perturbation theory. Remarkably enough, those for the relatively large fermion bare mass away from the chiral limit actually exhibit a finite-size hyperscaling relation, suggesting a large anomalous dimension $\gamma_m \sim 1$. This implies that there exists a remnant of the infrared conformality, and suggests that a typical technicolor, ``one-family model'', as modeled by the $N_f=8$ QCD can be a walking technicolor theory
Lattice study of conformality in twelve-flavor QCD
Ohki, Hiroshi (KMI)
The many-flavor SU(3) gauge theory near the conformal phase boundary is of great interest with regard to the dynamical origin of the electroweak symmetry breaking. We study the infrared conformality of the twelve-flavor QCD on the lattice, utilizing the highly improved staggered quarks (HISQ) type action which is useful to study the continuum physics. The finite size scaling test in the conformal hypothesis is performed for our data of hadron spectra at several values of lattice spacing and fermion mass. Our result is consistent with the conformal hypothesis. We then discuss possible corrections to the hyperscaling relation.
The Gradient Flow and the Running Coupling
Rantaharju, Jarno (The RIKEN Advanced Institute for Computational Science)
Recently, Yang-Mills gradient flow has been shown to have several interesting applications to lattice field theory. We will introduce the gradient flow and discuss some of its properties. We will then discuss the gradient flow coupling scheme in more detail and present studies of different definitions of the coupling in the SU(2) lattice field theory.
NLSUSY Nambu-Goldstone fermion composite model of nature-Nonlinear SUSY general relativity theory-
Shima, Kazunari (Saitama Institute of Technology)
New paradigm of the SUSY unification of space-time and matter is presented. Nonlinear representation of SUSY(NLSIUSY) for Nambu-Goldstone fermion describes uniquely the robust spontaneous SUSY breakdown(SSB) originating from the structure of basic space-time. NLSUSY unifies simply the gravity and the NG fermion and produces nonlinear supersymmetric general relativity theory(NLSUSYGR) possessing the form of the familiar Einstein-Hilbert action equipping the cosmological term. NLSUSYGR is highly nonlinear and nonrenormalizable action for graviton and NG fermion. However in the true vacuum it reproduces the familiar linear SUSY renormalizable theory with the robust SSB, where all particles of linear SUSY theory are composites of NG fermion. Namely, the true vacuum is achieved by forming the SSB LSUSY model as the composites of NG fermion. Our model gives new insight into the unsolved problems of particle physics and cosmology, e.g. SSB scale, the number of the generation of quarks and leptons, the proton decay, neutrino mass, dark energy density and chi ral eigenstates for fermions, etc. We discuss quickly the basic idea, some physical consequences and the future prospect.
Renormalization-Group Flows of Gauge Theories
Shrock, Robert (C. N. Yang Institute for Theoretical Physics, Stony Brook Univ., Stony Brook, NY, USA)
I will present results on calculations of renormalization-group flows of nonabelian and and abelian gauge theories with various fermion contents,including higher-loop computations, beta function zeros, and studies of scheme transformations. The discussion will include both vectorial and chiral gauge theories.
Exploring Colorons at the LHC
Simmons, Elizabeth (Michigan State University)
Many theories of physics beyond the standard model include new strong dynamics in the form of an extended color sector. In some instances, the enlarged color sector may be connected with electroweak symmetry breaking, composite Higgs sectors, and flavor physics. After mentioning a few illustrative models, this talk focuses on the hadron collider phenomenology of the extended color sector, including a variety of ways to detect massive color-octet vector resonances, establish that they are colored, and determine their couplings to fermions.
LHC Results and Future Prospects for Searches beyond the Standard Model
Terashi, Koji (University of Tokyo)
Since the observation of a Higgs particle with a mass of 126 GeV in LHC Run I, one of the most pressing tasks ahead for the ATLAS and CMS experiments in Run II is to reveal the nature of this particle and its role in electroweak symmetry breaking as precisely as possible. Probing the composite dynamics of the Higgs particle is also a very important subject in upcoming LHC run. In this talk I will review results from direct searches beyond the Standard Model at ATLAS and CMS in Run I and discuss future prospects in Run II and beyond. Some emphasis is placed on searches with signatures sensitive to certain classes of strongly coupled theories like technicolor.
Study of SU(2) gauge theory with six flavors
Yamada, Norikazu (KEK)
Among various candidates for realistic technicolor theories, we focus on SU(2) gauge theory with six flavors and present the lattice calculations of the running coupling and mass and of the low-lying meson spectrum. We point out that these two independent calculations indicate the existence of the infrared fixed point. In particular, the detailed comparison between two- and six-flavor theories is discussed.
Light composite flavor-singlet scalar in large N_f QCD
Yamazaki, Takeshi (KMI, Nagoya University)
The existence of a light flavor-singlet scalar is expected in the walking technicolor as a pseduo Nambu-Goldstone boson of the scale symmetry breaking. The scalar in the walking technicolor corresponds to Higgs boson in the standard model, whose mass is relatively light, about 125 GeV, comparing to the electroweak scale. We study flavor-singlet scalar in the twelve- and eight-flavor QCD using non-perturbative lattice gauge simulation with a highly improved staggered action. In both the theories, we found a light scalar comparing with the pion measured at finite fermion mass. This property is much different from the usual QCD. We consider the lightness of the scalar is a reflection of the (approximate) infrared conformality in the theory. Since the eight-flavor QCD may be a candidate of the walking technicolor, this result could support a possibility of the composite Higgs boson.