Lattice QCD with 8 and 12 degenerate quark flavors

TL;DR

This study compares lattice QCD simulations with 8 and 12 degenerate quark flavors, revealing a significant scale change across a rapid cross-over and evidence of chiral symmetry breaking at weak coupling.

Contribution

It provides a comparative analysis of QCD with different flavor numbers, highlighting the scale change and chiral symmetry breaking behavior using extensive lattice simulations.

Findings

Large scale change with 12 flavors across the cross-over

Evidence of chiral symmetry breaking at weak coupling

Distinct behaviors between 8 and 12 flavor cases

Abstract

We compare extensive simulations of QCD with 8 and 12 flavors of degenerate quarks, using the DBW2 gauge action, naive staggered fermions, and the rational hybrid Monte Carlo algorithm. A variety of values of the coupling constant, quark mass, and lattice size have been used. Our data suggests that, as the bare coupling is decreased, a rapid cross-over, which dramatically changes the lattice scale, exists with both 8 and 12 flavors. The scale change across this cross-over is much larger with 12 flavors than it is with 8 flavors. All of the observables we have measured, in both the zero and finite temperature systems, are consistent with a chiral symmetry breaking phase for the zero temperature theory on the weak coupling side of the rapid cross-over.