Confining vs. conformal scenario for SU(2) with adjoint fermions. Gluonic observables

TL;DR

This paper investigates whether SU(2) gauge theory with two adjoint fermions is confining or IR-conformal, using lattice simulations to analyze gluonic and mesonic observables relevant for walking technicolor models.

Contribution

It provides a comparative analysis of gluonic and mesonic sectors to identify the IR fixed point in SU(2) with adjoint fermions, advancing understanding of its conformal or confining nature.

Findings

Proposes a method to detect IR fixed points via gluonic and mesonic signals

Discusses systematic errors in lattice simulations

Reviews technical aspects of the calculations

Abstract

Walking technicolor is a mechanism for electroweak symmetry breaking without Higgs field. The Higgs mechanism is provided by chiral symmetry breaking in the technicolor theory. An essential ingredient is the vicinity to an IR fixed point, which could reconcile technicolor with the electroweak precision tests. SU(2) gauge theory with two Dirac adjoint fermions has been proposed as a candidate for walking technicolor. Understanding whether this theory is confining or IR-conformal is a challenging problem, which can be addressed by means of numerical simulations. We have pointed out that a clean signal for the existence of an IR fixed point in this theory can be obtained by comparing the mesonic and gluonic sectors. We review some technical details of our calculations. Possible systematic errors are discussed.