Quark Confinement in Multi-Flavor Quantum Chromodynamics

TL;DR

This study explores how the number of quark flavors affects confinement and phase transitions in lattice QCD, revealing different transition orders and behaviors for varying flavor counts.

Contribution

It extends previous lattice QCD results by analyzing the flavor dependence of confinement and phase transition characteristics.

Findings

For N_f ≤ 6, the deconfining transition crosses the chiral limit at finite β.

The transition is continuous for N_f=2 and first order for N_f=6.

For N_f ≥ 7, the deconfining transition extends up to β=4.5 with a critical quark mass of order inverse lattice spacing.

Abstract

It is investigated how quark confinement depends on the number of flavors, $N_f$, in QCD on the lattice with Wilson quarks. We strengthen and extend the conclusion reported at {\it Lattice 91}: (1) For $N_f \le 6$ the finite temperature deconfining transition/crossover line crosses the chiral limit at finite $\beta$. We identify the crossing point for $N_f=2$ and 6 on a $T=4$ lattice, where $T$ is the lattice size in the temporal direction. We find the phase transition at the crossing point is continuous for $N_f=2$, while it is of first order for $N_f=6$. (2) For $N_f \ge 7$, the $T$-independent deconfining transition observed at $\beta=0$ extends up to $\beta=4.5$ with the critical quark mass $m_{\rm quark} = O(a^{-1})$, where $a$ is the lattice spacing.