The spectrum and mass anomalous dimension of SU(2) adjoint QCD with two Dirac flavours

TL;DR

This study uses lattice simulations to analyze the particle spectrum and mass anomalous dimension of SU(2) gauge theory with two adjoint Dirac fermions, revealing new states and the importance of scaling corrections.

Contribution

It provides the first detailed lattice investigation of the spectrum and anomalous dimension in SU(2) adjoint QCD with two flavors, including the effects of scaling corrections.

Findings

Discovery of new exotic fermion-gluon states

Determination of the mass anomalous dimension from scaling

Identification of scaling correction effects on universal ratios

Abstract

In this work we present the results of our investigation of \su{2} gauge theory with two Dirac fermions in the adjoint representation (aQCD2), which belongs to the class of strongly interacting gauge theories that are of basic interest for extensions of the Standard Model. We have done numerical lattice simulations of this theory at two different values of the gauge coupling and several fermion masses. Our results include the particle spectrum and the mass anomalous dimension. The spectrum contains new exotic fermion-gluon states and flavour-singlet mesons. The mass anomalous dimension is determined from the scaling of the masses and the mode number. The remnant dependence of the universal mass ratios and mass anomalous dimension on the gauge coupling indicates the relevance of scaling corrections, such that earlier estimations for the universal fixed point value of the mass anomalous dimension are incomplete without their inclusion.