Wed·Nov 7, 2007Wednesday·November 7, 2007

1. 01*

   Finite Temperature Sum Rules in Lattice Gauge Theory

   Harvey B. Meyer🇺🇸

   We derive non-perturbative sum rules in SU($N$) lattice gauge theory at finite temperature. They relate the susceptibilities of the trace anomaly and energy-momentum tensor to temperature derivatives of the thermodynamic potentials. Two of them have been derived previously in the continuum and one is new. In all cases, at finite latttice spacing there are important corrections to the continuum sum rules that are only suppressed by the bare coupling $g_0^2$. We also show how the discretization errors affecting the thermodynamic potentials can be controlled by computing these susceptibilities.

   hep-latNPB(2008)·27 citations
2. 02*

   Finite temperature SU(2) gauge theory: critical coupling and universality class

   Alexander Velytsky🇺🇸

   We examine SU(2) gauge theory in 3+1 dimensions at finite temperature in the vicinity of critical point. For various lattice sizes in time direction ($N_{\tau }=1,2,4,8$) we extract high precision values of the inverse critical coupling and critical values of the 4-th order cumulant of Polyakov loops (Binder cumulant). We check the universality class of the theory by comparing the cumulant values to that of the 3D Ising model and find very good agreement. The Polyakov loop correlators for the indicated lattices are also measured and the string tension values extracted. The high precision values of critical coupling and string tension allow us to study the scaling of dimensionless $T_c/\sqrt{\sigma }$ ratio. The violation of scaling by <10% is observed as the coupling is varied from weak to strong coupling regime.

   hep-latInt.J.Mod.Phys.C(2008)·26 citations
3. 03*

   Progress in hadron structure physics on the lattice

   Philipp Hägler🇩🇪

   This is a review of progress in hadron structure physics from lattice QCD. Recent results on the structure of the nucleon and the pion in terms of (transition) form factors, moments of distribution amplitudes and (generalized) parton distribution functions are presented. These observables allow us to investigate a number of fundamental physics questions related to e.g. the distribution of charge and momentum in hadrons, the spin structure of the nucleon and the pion, and correlations between spin, orbital angular momentum and coordinate degrees of freedom. Chiral extrapolations of selected lattice results are presented and compared to results from experiment and phenomenology. We conclude that lattice simulations already today strongly contribute to our understanding of the structure of hadrons.

   hep-lathep-phPoS(2007)·29 citations
4. 04*

   Eigenvalue repulsion in an effective theory of SU(2) Wilson lines in three dimensions

   Adrian Dumitru🇩🇪 · Dominik Smith🇩🇪

   We perform simulations of an effective theory of SU(2) Wilson lines in three dimensions. We include a non-perturbative "fuzzy-bag" contribution which is added to the one-loop perturbative potential for the Wilson line. We confirm that, at moderately weak coupling, this leads to eigenvalue repulsion in a finite region above the deconfining phase transition which shrinks in the extreme weak-coupling limit. A non-trivial Z(N) symmetric vacuum arises in the confined phase.

   hep-lathep-phPRD(2008)·21 citations
5. 05*

   Gauge symmetry and Slavnov-Taylor identities for randomly stirred fluids

   A. Berera (Edinburgh)🇬🇧 · D. Hochberg (CAB, Madrid)🇪🇸

   The path integral for randomly forced incompressible fluids is shown to have an underlying Becchi-Rouet-Stora (BRS) symmetry as a consequence of Galilean invariance. This symmetry must be respected to have a consistent generating functional, free from both an overall infinite factor and spurious relations amongst correlation functions. We present a procedure for respecting this BRS symmetry, akin to gauge fixing in quantum field theory. Relations are derived between correlation functions of this gauge fixed, BRS symmetric theory, analogous to the Slavnov-Taylor identities of quantum field theory.

   ↳ hep-thcond-mat.stat-mechhep-lathep-ph+1PRL(2007)·20 citations
6. 06*

   Universal properties of bulk viscosity near the QCD phase transition

   F. Karsch🇺🇸 · D. Kharzeev🇺🇸 · K. Tuchin🇺🇸

   We extract the bulk viscosity of hot quark-gluon matter in the presence of light quarks from the recent lattice data on the QCD equation of state. For that purpose we extend the sum rule analysis by including the contribution of light quarks. We also discuss the universal properties of bulk viscosity in the vicinity of a second order phase transition, as it might occur in the chiral limit of QCD at fixed strange quark mass and most likely does occur in two-flavor QCD. We point out that a chiral transition in the O(4) universality class at zero baryon density as well as the transition at the chiral critical point which belongs to the Z(2) universality class both lead to the critical behavior of bulk viscosity. In particular, the latter universality class implies the divergence of the bulk viscosity, which may be used as a signature of the critical point. We discuss the physical picture behind the dramatic increase of bulk viscosity seen in our analysis, and devise possible experimental tests of related phenomena.

   ↳ hep-phhep-latnucl-thPLB(2008)·412 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.