A new method for the beta function in the chiral symmetry broken phase

¹ University of Wuppertal, Department of Physics, Wuppertal D-42097, Germany
² Juelich Supercomputing Center, Forschungszentrum Juelich, Juelich D-52425, Germany
³ University of the Pacific, 3601 Pacific Ave, Stockton CA 95211, USA
⁴ University of California, San Diego, 9500 Gilman Drive, La Jolla CA 92093, USA
⁵ Eötvös University, Institute for Theoretical Physics, MTA-ELTE Lendulet Lattice Gauge Theory Research Group, Budapest 1117, Hungary
⁶ Universidad Autonoma, IFT UAM/CSIC and Departamento de Fisica Teorica, 28049 Madrid, Spain

Published online: 26 March 2018

Abstract

We describe a new method to determine non-perturbatively the beta function of a gauge theory using lattice simulations in the p-regime of the theory. This complements alternative measurements of the beta function working directly at zero fermion mass and bridges the gap between the weak coupling perturbative regime and the strong coupling regime relevant to the mass spectrum of the theory. We apply this method to SU(3) gauge theory with two fermion flavors in the 2-index symmetric (sextet) representation. We find that the beta function is small but non-zero at the renormalized coupling value g² = 6.7, consistent with our previous independent investigation using simulations directly at zero fermion mass. The model continues to be a very interesting explicit realization of the near-conformal composite Higgs paradigm which could be relevant for Beyond Standard Model phenomenology.