Andreas Gocksch

How to make large domains of disoriented chiral condensate

Rajagopal and Wilczek have proposed that relativistic nuclear collisions can generate domains in which the chiral condensate is disoriented. If sufficiently large (i.e., nucleus sized), such domains can yield measurable fluctuations in the number of neutral and charged pions. However, by numerical simulation of the zero-temperature two-flavor linear sigma model, we find that domains are essentially [ital pion] sized. Nevertheless, we show that large domains can occur if the effective mesons masses are much lighter.

Z(N) interface tension in a hot SU(N) gauge theory

Abstract The interface tension between Z( N ) vacua in a hot SU( N ) gauge theory (without dynamical fermions) is computed at next to leading order in weak coupling. The Z( N ) interface tension is related to the instanton of an effective action, which includes both classical and quantum terms; a general technique for treating consistently the saddle points of such effective actions is developed. Loop integrals which arise in the calculation are evaluated by means of zeta-function techniques. As a byproduct, up to two-loop order we find that the stable vacuum is always equivalent to the trivial one, and so respects charge-conjugation symmetry.

Spontaneous Breaking of Parity in Quenched Lattice {QCD} With Wilson Fermions

Abstract By using a parity breaking magnetic field H in the Wilson fermion action we establish the spontaneous breakdown of parity at K c in the limit H ↦0.

Partition function for the eigenvalues of the Wilson line

Abstract In a gauge theory at nonzero temperature the eigenvalues of the Wilson line form a set of gauge invariant observables. By constructing the corresponding partition function for the phases of these eigenvalues, we prove that the trivial vacuum, where the phases vanish, is a minimum of the free energy.

Phase diagram of the N = 2 Kazakov-Migdal model

We have determined the phase diagram of the simplest version of a lattice model recently introduced by Kazakov and Migdal. Denoting by

More on parity and Wilson fermions. Quenched simulations in finite temperature QCD

{\mathit{m}}_{0}

An effective strong coupling lattice model for finite temperature QCD

and \ensuremath{\lambda} the mass and the coupling of the scalar field in the model, we find a line of first-order phase transitions in the (

An effective spin model for the finite temperature twisted Eguchi-Kawai model

{\mathit{m}}_{0}

Weak coupling analysis of the finite-temperature twisted Eguchi-Kawai model☆

,\ensuremath{\lambda}) plane ending in a critical point where \ensuremath{\lambda} is nonzero. Kazakov and Migdal speculate that their model of scalar field theory could induce QCD. Our work indicates that there is no continuum limit except at the critical end point. Whether or not a nontrivial continuum limit exists, there requires a careful study of the renormalization-group properties of the model.

The deconfining phase transition in the finite temperature twisted Eguchi-Kawai model

Abstract We study the properties of Wilson fermions under space reflection (parity) in quenched, finite temperature lattice QCD. The spontaneous breaking of parity at the critical hopping parameter observed at zero temperature is shown to be absent at high temperatures. The splitting of hadrons differing only in their parity assignment is much reduced over the zero temperature case but a finite gap remains. We interpret this as the effect of chiral symmetry breaking terms that remain a finite gauge coupling but vanish with the lattice spacing.