Conveners
Parallels Track A: Monday I
- Jeff Greensite (San Francisco State University)
Parallels Track A: Monday II
- Manfried Faber (Techn Univ Wien)
Parallels Track A: Tuesday I
- Dmitry Antonov ()
Parallels Track A: Tuesday II
- Jeff Greensite (San Francisco State University)
Parallels Track A: Thursday I
- Manfried Faber (Techn Univ Wien)
Parallels Track A: Thursday II
- Jeff Greensite (San Francisco State University)
Parallels Track A: Thursday III
- Dmitry Antonov ()
Parallels Track A: Friday I
- robert pisarski (brookhaven national laboratory)
Parallels Track A: Friday II
- Manfried Faber (Techn Univ Wien)
Parallels Track A: Friday III
- Dmitry Antonov ()
I discuss how objects with topological charge 1/N can arise in CP(N-1) models in 1+1 dimensions, and in SU(N) gauge theories, without dynamical quarks, in 3+1 dimensions. The ansatz involves multivalued functions: a Z(N) vortex in the former, and a Z(N) monopole in the latter. Unlike classical instantons, such a quantum instanton has a fixed size on the order of the scale for confinement. ...
In this talk I will discuss how mixed 0-form/1-form anomalies arise in the Hilbert space of gauge theories in 4d for arbitrary gauge group. I will show how the anomalies reveal an exact degeneracy of states for an arbitrary torus size. Finally, I will discuss some of the implications of our results for semiclassics, the infinite volume limit, and dualities.
After examining the mass and pressure decompositions of hadrons in the stress-energy-momentum tensor, it is found that the glue part of the trace anomaly can be identified as originated from the vacuum energy of the glue condensate and gives a CONSTANT restoring pressure which balances that from the traceless part of the Hamiltonian (quark and glue kinetic energies) to confine the hadron, much...
In this talk I will give an overview on recent results on the spectrum and properties of
conventional mesons and exotic mesons (glueballs and four-quark states) as obtained in
the framework of Dyson-Schwinger and Bethe-Salpeter equations with particular focus on
states with the quantum numbers of a scalar.
I will discuss the spectrum of (quenched) glueballs and compare with results from...
Confinement of 4d gauge theories is usually the strong-coupling problem, and it is a difficult task to understand even its qualitative features. We are trying to develop its semiclassical understanding based on the idea of volume independence or adiabatic continuity. We conjecture that the strong-coupling regime of many 4d gauge theories is continuously connected to the weak-coupling theories...
We consider the massless charge-N Schwinger model and its deformation with two four-fermion operators. Without the deformations, this model exhibits chiral symmetry breaking without confinement. It is usually asserted that the massless Schwinger model is always deconfined and a string tension emerges only when a mass for the fermion field is turned on. We show that in the presence of these...
Ample numerical evidence from lattice calculations shows a strong connection between the confining properties of gauge theories at finite temperature and the localisation properties of the low-lying Dirac eigenmodes. In this talk I review recent progress on this topic, including results for QCD at imaginary chemical potential ${\mu}_I/T = \pi$ at temperatures above the Roberge-Weiss transition...
In order to understand the puzzle of the free energy of an individual quark in QCD, we explicitly construct ensembles with quark numbers $N_V\neq 0\!\!\mod\! 3$, corresponding to non-zero triality in a finite subvolume $V$ on the lattice. We first illustrate the basic idea in an effective Polyakov-loop theory for the heavy-dense limit of QCD, and then extend the construction to full Lattice...
We test a method for computing the static quark-antiquark potential in lattice QCD, which is not based on Wilson loops, but where the trial states are formed by eigenvector components of the covariant lattice Laplace operator. The runtime of this method is significantly smaller than the standard Wilson loop calculation, when computing the static potential not only for on-axis, but also for...
We study new symmetries of the Cardy-Rabinovici model and their dynamical applications. The Cardy-Rabinovici model is a 4d $U(1)$ gauge theory with electric and magnetic matters, which is a good playground for studying the dynamics of the Yang-Mills theory with $\theta$ angle. In this model, the electromagnetic $SL(2, \mathbb{Z})$ self-duality is not realized in a naive way. Still, the $SL(2,...
In gauge Higgs theories there is the possibility that there may exist localized excitations of the gauge and Higgs fields surrounding a static charge, and this would lead to excited states of what are usually described as "elementary" particles. This possibility is illustrated by a numerical simulation of the Landau-Ginzburg model of superconductivity, which in turn suggests certain...
We systematically explore real and complex saddle points for the Hubbard model on hexagonal lattice at zero and non-zero chemical potential. As a result of this study, we formulate the saddle point approximation to the path integral, which is essentially the gas of weakly interacting instantons. Since bosonic part of the action is Gaussian, Euclidean field equations for instantons should...
The low-energy regime of QCD is known as the nonperturbative region of QCD because the standard perturbation theory based on the gauge-fixed Lagrangian by the Faddeev-Popov procedure finds a Landau pole at small scales. However, numerical simulations show that the coupling constant, i.e. the one obtained through Taylor's Theorem, remains finite in the infrared. In particular, the development...
It is a fundamental question: what is the origin of the glueball masses? In the pure Yang-Mills theory, there is no mass scale in the classical level, while the breaking of scale invariance is induced by quantum effects. This is regarded as the trace anomaly, which is associated with the non-vanishing trace of the energy-momentum tensor (EMT) operator. In this context, the origin of the...
The QCD vacuum has been energetically studied by lattice QCD simulations
with projection methods, such as Abelian projection and center projection.
We propose a new-type projection in the Coulomb gauge, in which gauge configurations are expanded in terms of Faddeev-Popov eigenmodes and only some eigenmodes are kept. With lattice QCD simulations at the quenched level, we apply this...
The Renormalization Group Procedure for Effective Particles (RGPEP) provides the connection between low- and high-energy interactions in QCD through the construction of effective particles [1,2].
The approach reproduces the correct behavior of the coupling constant at high energies (asymptotic freedom) [3] and, at the current level of approximation, the second-order solution of the...
Thanks to the recent development of lattice simulation techniques, numerical simulations on an anisotropic system, where the temporal and z directions are compactified while the remaining x and y directions are left infinitely large, have become possible. Such system is understood as an extension of finite-temperature one where only the temporal direction is compactified; namely, the...
The Casimir effect is a remarkable macroscopic feature of QED, while recent lattice studies have also shown its potential nontrivial consequences in QCD.
In light of having a better understanding of the Casimir effect,
it is advantageous to have a self-contained path integral formulation of the phenomenon.
In this talk I will show how the Casimir effect between two uncharged plates in the...
Compact U(1) gauge theory in 3+1 dimensions possesses the confining phase characterized by a linear raise of the potential between particles with opposite electric charges at sufficiently large inter-particle separation. This phenomenon is closely related to the color confinement in non-Abelian gauge theories such as QCD. In QED, the condensation of Abelian monopoles at strong gauge coupling...
The four types of maximally nontrivial calorons in SU(2)-QCD have characteristic spatial distribution of Polyakov loops. We describe a classical geometric model of an SU(2)-field with finite, stable solitonic solutions with the same structure as these four types of calorons. These solitons are characterised by two topological quantum numbers which can be compared with electric charge and spin....
The quark confinement in QCD is achieved by concentration of the chromoelectric field between the quark-antiquark pair into a flux tube, which gives rise to a linear quark-antiquark potential. We study the structure of the flux tube created by a static quark-antiquark pair in the pure gauge SU(3) theory, using lattice Monte-Carlo simulations. We calculate the spatial distribution of all three...
We compare the behavior of zero-modes of the overlap Dirac operator measured on the finite temperature 2+1 flavor lattice QCD configurations, generated with domain wall fermion discreitzation, to the local Polyakov Loop in the temperature range 1.1-1.2T_c, T_c being the pseudo-critical temperature. We show how the position of the zero-modes are anti-correlated to the local value of the Polyakov Loop.
It is known that 1+1 dimensional real scalar models with a negative mass squared have a soliton solution called the kink. We analyze the distribution of the energy-momentum tensor around the kink by incorporating the quantum correction up to leading order. The Fourier transform of the distribution corresponds to the gravitational form factors. We employ the collective coordinate method which...
Meissner effect for the chromoelectric field is the property of the non-perturbative QCD vacuum postulated to describe color confinement. We follow London's macroscopic theory of the Meissner effect for the magnetic field in superconductors and obtain the dual Meissner effect by fixing the phenomenological color gluon current assumed relevant at strong coupling. Its non-Abelian piece is simply...
We report novel lattice QCD results for the position-space gluon propagator from quenched lattice-QCD simulations. Using standard Wilson action, we have computed the gluon propagator in position space with a detailed treatment of discretization errors.
We discuss on the usefulness of the long-distance behavior of gluon propagator for constraining the deep infrared running of the gluon...
Quantum Chromodynamics permits the formation of charge-parity violating domains inside the medium produced in heavy-ion collisions resulting in an imbalanced quark chirality. With the precense of a strong magnetic field (as strong as $10^{15}$ T) produced by the spectator protons in off-central heavy-ion collisions, this would lead to an electric-charge separation along the direction of the...
The photon propagator for the pure gauge theory is revisited using large lattices. For the confined case we show that it has an associated linearly growing potential, it has a mass gap, that is related to the presence of monopoles, and its spectral function violates positivity. In the deconfined phase, our simulations suggest that a free field theory is recovered in the thermodynamic limit.
