Continuous Advances in QCD 2016
Persistent link for this collectionhttps://hdl.handle.net/11299/180305
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Item All order linearised hydrodynamics from fluid-gravity correspondence(2016-05-14) Lublinsky, MichaelRelativistic fluid dynamics emerges as an effective theory describing strongly coupled QFTs at finite temperature. Following a brief intro into relativistic fluid dynamics, I will discuss how constitutive relation/transport coefficients of a fluid can be obtained using the holographic methods. Applying the fluid/gravity correspondence, we have determined the (linearized) stress energy tensor of N=4 super-Yang-Mills theory at strong coupling accounting for all orders in derivatives of the fluid velocity. I will introduce momenta-dependent transport functions, such as generalized shear viscosity, and will derive closed form linear holographic RG|flow-type equations for these functions.Item Anomalous magnetic moment of a bound electron(2016-05-12) CZARNECKI, ANDRZEJThe mass of the electron is best determined with hydrogen-like ions in|a Penning trap. Binding in an ion removes the error due to the thermal|motion of the electron. However, the price is that some properties of|the electron are modified by the binding. These changes can be|computed in QED but there are interesting complications due to the|binding. I will present a new determination of the g-factor of a bound|electron. This calculation is motivated by the 2014 improvement in the|mass of the electron and makes further experimental progress|possible. Bound-state studies have traditionally been a mix of art and|science, and part of our motivation is to make them more algorithmic.Item Approaching conformality in lattice models(2016-05-14) Meurice, YannickWe discuss new renormalization group methods designed to study near conformal situations in two dimensional spin models and four dimensional multi flavor gauge theories.Item Aspects of the sign problem in QCD(2016-05-13) Cohen, ThomasThe sign problem in QCD is important since it inhibits our ability to use numerical lattice gauge theory methods to describe many significant problems including QCD matter at nonzero baryon chemical potential. In this talk, the sign problem is explored for QCD with a theta term--a more straightforward problem than the case of the chemical potential. Various subtle effects arise in the infinite volume limit which at first blush seem highly counter-intuitive. This talk will elucidate these effects.Item Axion EFT and Dense Axion Stars(2016-05-12) Braaten, EricAxions can be described by a relativistic field theory with a real scalar field whose self-interaction potential is a periodic function. If axionic dark matter is a Bose-Einstein condensate, it can be described more simply by a nonrelativistic effective field theory with a complex scalar field. A stable axion star is a gravitationally bound Bose-Einstein condensate of axions. In previously known axion star solutions, the attractive forces of gravity and axion pair interactions are balanced by the kinetic axion pressure. A new class of axion stars has been discovered in which the attractive forces are balanced by the mean-field pressure of the axion Bose-Einstein condensate.Item Continuous chiral symmetry breaking in a calculable regime(2016-05-14) Cherman, AlekseyI will discuss work with M. Unsal on a semiclassically-calculable regime of 4D QCD, obtained by an adiabatic circle compactification, in which continuous chiral symmetry breaking can be studied systematically.Item Correlations in hadronic wave function(2016-05-14) Kovner, AlexI discuss within the Color Glass approach, how Bose-Einstein correlations between gluons in hadronic wave function can exhibit themselves as observable correlations between emitted particles in the final state.Item Coulomb branch, Higgs branch, and nilpotent orbits(2016-05-12) Hanany, AmihayTheories with 8 supercharges have moduli spaces of vacua which generically divide into two branches - the so called Coulomb branch and the Higgs branch. These branches are HyperKahler in the cases of Higgs branch in dimensions 3 up to 6, and Coulomb branch in 3. They become cones when one sets the FI terms and masses to zero. There is a natural SU(2)_R which acts on 3 complex structures. We will devote our talk to general aspects of HyperKahler cones and discuss quiver gauge theories where these spaces arise as moduli spaces in one or more of these branches. Special attention is given to moduli spaces in which the generators of the chiral carry spin 1 under SU(2)_R, and consequently transform in the adjoint representation of the global symmetry group. They shall be termed mesonic moduli spaces. It turns out that there is a full classification of these spaces which goes under the name of “nilpotent orbits”. We will discuss general aspects of these spaces and the new exciting directions that these results can take us.Item Critical string from non-Abelian vortex in four dimensions(2016-05-15) Yung, AlexeiIt is shown that non-Abelian string supported in N=2 supersymmetric QCD with U(N) gauge group and |number of quark multiplets 2N can behave as a fundamental superstring. In addition to translational moduli the non-Abelian string carry also orientational/ size moduli. Their dynamics is described by two dimensional weighted CP(N,N) model on the string world sheet. For N=2 the dimension of orientational/ size moduli space is six and can be combined with four translational moduli to form a ten dimensional space required for a superstring to be critical. For this case CP(2,2) model|on the string world sheet is defined on the non-compact Calabi-Yau conifold. We study the closed string states which emerges in four dimensions and identify them with mesons of the bulk theory. We find one massless hypermultiplet associated with the deformation of the complex structure of the conifold.Item Cusp anomalous dimension in QCD and its supersymmetric extensions(2016-05-12) KORCHEMSKY, GREGORYItem Decay of a bound muon(2016-05-12) Szafron, RobertRecently, progress has been achieved in the theory​ of the​ bound muon decay​. ​Bound states of heavy quarks share many properties with muonic atoms. QCD methods developed to describe semi-leptonic decays of heavy quarks can be applied to QED systems involving muons. Moreover, the muon decay spectrum and the wave function are known analytically. I will show how these techniques can be used to calculate the electron spectrum in the decay of a bound muon, at the leading order and with dominant radiative corrections. In my talk I will present recent results for ​a ​muon bound ​with an aluminum nucleus, the planned target in muon-electron conversion searches.Item Dilaton, conformal symmetry and Weyl invariance(2016-05-14) Monin, AlexanderI’ll show how to implement spontaneous breaking of conformal symmetry at the quantum level from the IR perspective. In other words how to introduce consistently the (massless) dilaton. Given the importance of the Weyl invariance in the construction it is necessary to understand the relation between conformal symmetry and Weyl invariance. I’ll touch upon the issue and present examples of theories that are conformally invariant but do not admit Weyl invariant generalizations.Item Geometry and Dynamics of a Coupled 2D and 4D Quantum Field Theory(2016-05-12) Konishi, KenichiGeometric and dynamical aspects of a coupled 4D-2D interacting quantum field theory - the gauged nonAbelian vortex will be discussed. The fluctuations of the internal 2D nonAbelian vortex zeromodes excite the massless 4D Yang-Mills modes, which give rise to divergent energies. This means that the well-known 2D CP(N-1) zeromodes associated with a nonAbelian vortex become nonnormalizable. At the same time, all sorts of global, topological 4D effects such as the nonAbelian Aharonov-Bohm effect come into play. These topological, global features and the dynamical properties of the fluctuations of the 2D vortex moduli are intimately correlated, as shown concretely here in a U(1) xSU(N) x SU(N) model with scalar fields in a bifundamental representation of the two SU(N) factor gauge groups.Item A hidden symmetry of crazy QCD(2016-05-13) Glozman, LeonidWe discuss recent lattice results on removal of the near-zero modes|of the Dirac operator and their theoretical interpretation and implications.Item How supersymmetry helps to understand hydrodynamics(2016-05-15) Koroteev, PeterWe discuss the connection between periodic finite-difference Intermediate Long Wave hydrodynamical systems and integrable many-body models of Calogero and Ruijsenaars-type. The former describe quantum cohomology and quantum K-theory of the ADHM moduli space of Abelian instantons, while the latter arise in the the instanton counting in four and five dimensional supersymmetric gauge theories with eight supercharges in the presence of defects. Using string theory dualities we provide correspondences between hydrodynamical and many-body integrable systems. In particular, we match the energy spectra on both sides.Item Instanton-dyons generate both deconfinement and chiral symmetry restoration transitions(2016-05-12) Shuryak, EdwardThe main topic of the talk is to present results on the deconfinement and chiral phase transitions in the model based on instanton-dyons. Those include analytic mean-field analysis, for SU(2) gauge theory arXiv: 1503.03058 and QCD with quarks arXiv:1503.09148 due to Yizhuang Liu, Ismail Zahed and myself, and also numerical simulations with Rassmus Larsen arXiv:1504.03341 and arXiv:1511.02237. I also hope, in brief form, to describe a methodical paper on new version of semiclassical theory based on so called “flucton” configurations, arXiv:1601.03964.Item Instanton-torus knot duality in SQCD(2016-05-14) Gorsky, AlexanderItem Large-N CP(N-1) sigma model on a finite interval with the Dirichlet condition(2016-05-15) Ohashi, KeisukeWe study the large-N solution of the bosonic CP(N-1) model on a finite interval |with the Dirichlet conditions. In the literature, this model has been studied with translational invariant ansatz and there an existence of phase transition was found. |We find that this |translational invariant ansatz can not give a solution of the gap equation and |divergence behavior appears around the boundaries, and resultantly |the phase transition do not appear in this system.Item Lessons from numerical holography(2016-05-13) Yaffe, LaurenceGauge/gravity duality (or “holography”) allows one to calculate highly non-trivial far from equilibrium dynamics in strongly coupledgauge theory --- provided one can solve asymptotically anti-deSitter initial value problems in higher dimensional gravity. Recent results and work in progress in this area will be discussed, focusing on calculations motivated by the physics of heavy ion collisions and thermal gauge theories.Item Lessons from numerical holography(2016-05-13) Yaffe, LaurenceGauge/gravity duality (or “holography”) allows one to calculate highly non-trivial far from equilibrium dynamics in strongly coupledgauge theory --- provided one can solve asymptotically anti-deSitter initial value problems in higher dimensional gravity. Recent results and work in progress in this area will be discussed, focusing on calculations motivated by the physics of heavy ion collisions and thermal gauge theories.
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