Running coupling constant of ten-flavor QCD with the Schr\"odinger functional method

TL;DR

This study investigates the infrared behavior of ten-flavor SU(3) QCD using the Schrödinger functional method, providing evidence for an infrared fixed point which is relevant for walking technicolor theories.

Contribution

First lattice computation of the running coupling in ten-flavor QCD using the Schrödinger functional scheme, indicating the presence of an infrared fixed point.

Findings

Evidence of an infrared fixed point in ten-flavor QCD

First continuum limit analysis with this method for this theory

Supports the viability of walking technicolor models

Abstract

Walking technicolor theory attempts to realize electroweak symmetry breaking as the spontaneous chiral symmetry breakdown caused by the gauge dynamics with slowly varying gauge coupling constant and large mass anomalous dimension. Many-flavor QCD is one of the candidates owning these features. We focus on the SU(3) gauge theory with ten flavors of massless fermions in the fundamental representation, and compute the gauge coupling constant in the Schr\"odinger functional scheme. Numerical simulation is performed with $O(a)$-unimproved lattice action, and the continuum limit is taken in linear in lattice spacing. We observe evidence that this theory possesses an infrared fixed point.