The chiral phase transition for QCD with sextet quarks

TL;DR

This study investigates whether QCD with sextet quarks exhibits walking behavior or conformality by analyzing the coupling at the chiral transition across different lattice sizes.

Contribution

The paper presents lattice simulations of sextet quarks at multiple lattice sizes to determine the nature of the theory's infrared behavior.

Findings

Preliminary results on $N_t=8$ lattice improve transition position accuracy.

Ongoing simulations on $N_t=12$ lattice aim to clarify the coupling behavior.

The study seeks to distinguish between QCD-like and conformal dynamics.

Abstract

QCD with 2 massless colour-sextet quarks is studied as a model of Walking Technicolor. We simulate lattice QCD with 2 light color-sextet staggered quarks at finite temperature, and use the dependence of the coupling at the chiral transition on the temporal extent, $N_t$, of the lattice in lattice units to study the running of the bare lattice coupling with lattice spacing. Our goal is to determine whether this theory is QCD-like and `walks', or if it is conformal. If it is QCD-like, the coupling at the chiral transition should tend to zero as $N_t \rightarrow \infty$ in a manner controlled by asymptotic freedom, i.e. by the perturbative $\beta$-function. On the other hand, if this theory is conformal, this coupling will approach a non-zero limit in the $N_t \rightarrow \infty$ limit. We are extending our simulations on an $N_t=8$ lattice to determine the position of the chiral transition with greater accuracy, and are performing simulations on an $N_t=12$ lattice.