β function and equation of state for QCD with two flavors of quarks

Abstract

We measure the pressure and energy density of two flavor QCD in a wide range of quark masses and temperatures. The pressure is obtained from an integral over the average plaquette or 〈\ensuremath{\psi}\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\psi}〉. We measure the QCD \ensuremath{\beta} function, including the anomalous dimension of the quark mass, in new Monte Carlo simulations and from results in the literature. We use it to find the interaction measure, \ensuremath{\varepsilon}-3p, yielding nonperturbative values for both the energy density \ensuremath{\varepsilon} and the pressure p.