Determination of Anisotropy Coefficients for SU(3) Gauge Actions from the Integral and Matching Methods

Abstract

We use two non-perturbative methods to obtain the anisotropy derivatives of the coupling constants (the anisotropy coefficients) of SU(3) lattice gauge theory. These coefficients appear in the derivative formulae for the energy density and the pressure. We calculate them for the standard Wilson and two improved actions, the 2x2 and the Square Symanzik action. Both methods lead for all investigated actions to compatible results which are clearly different from their known asymptotic perturbative limits. With increasing beta the limits are however approached in all cases. Our findings strongly support the equivalence of the integral and derivative methods for the calculation of energy density and pressure.