Approaching the conformal window: systematic study of the particle spectrum in SU(2) field theory with Nf=2, 4 and 6

TL;DR

This study investigates the hadron spectrum and scale setting in SU(2) gauge theories with varying fermion flavors, providing insights into the conformal window and the transition from QCD-like behavior to conformality.

Contribution

It offers a systematic lattice study of the particle spectrum for Nf=2, 4, 6 in SU(2) gauge theory, near the conformal window, using gradient flow for scale setting.

Findings

Nf=2 case shows QCD-like spectrum

Nf=6 is close to the conformal window edge

Gradient flow effectively determines scale setting

Abstract

It is expected that SU(2) gauge theory with $N_f$ fundamental fermions has an infrared fixed point when $N_f$ is between $\sim 6$ and 10. We study the hadron spectrum and scale setting in SU(2) gauge field theory with $N_f=2,4,6$ using hypercubic stout smeared Wilson-clover (HEX) action. The case $N_f=2$ is QCD-like, whereas $N_f=6$ is close to the lower edge of the conformal window. In our study the length scales are determined by using the gradient flow approach.