A lower bound on T_SR/m_H in the O(4) model on anisotropic lattices

Abstract

Results of an investigation of the O(4) spin model at finite temperature using anisotropic lattices are presented. In both the large N approximation and numerical simulations using the Wolff cluster algorithm we find that the ratio of the symmetry restoration temperature T_SR to the Higgs mass m_H is independent of the anisotropy ξ. From the numerical simulations we obtain a lower bound of T_SR/m_H ≈ 0.58 ± 0.02 at a value for the Higgs mass m_Ha_s ≈ 0.5, which is lowered further by about 10% at m_Ha_s ≈ 1. Requiring certain timelike correlation functions to coincide with their spacelike counterparts, quantum and scaling corrections to the anisotropy are determined and are found to be small i.e., the anisotropy is found to be close to the ratio of spacelike and timelike lattice spacings.