Lattice Study of the Extent of the Conformal Window in Two-Color Yang-Mills Theory

TL;DR

This study uses lattice calculations to investigate whether SU(2) Yang-Mills theory with six massless fermions exhibits an infrared fixed point, focusing on the Schrödinger functional coupling and its sensitivity to fermion mass tuning.

Contribution

It provides a lattice-based analysis of the conformal window in SU(2) gauge theory with six fermions, highlighting challenges in coupling measurement at strong couplings.

Findings

Inconclusive evidence for an infrared fixed point due to coupling sensitivity

Demonstrates the difficulty of precise coupling measurement at strong bare couplings

Highlights the importance of tuning fermion mass in lattice studies

Abstract

We perform a lattice calculation of the Schr\"odinger functional running coupling in SU(2) Yang-Mills theory with six massless Wilson fermions in the fundamental representation. The aim of this work is to determine whether the above theory has an infrared fixed point. Due to sensitivity of the $SF$ renormalized coupling to the tuning of the fermion bare mass we were unable to reliably extract the running coupling for stronger bare couplings.