The HotQCD Equation of State Original Research Article

We present results from recent calculations of the QCD equation of state by the HotQCD Collaboration and review the implications for hydrodynamic modeling. The equation of state of QCD at zero baryon density was calculated on a lattice of dimensions 323×8 with ml=0.1ms (corresponding to a pion mass of View the MathML source) using two improved staggered fermion actions, p4 and asqtad. Calculations were performed along lines of constant physics using more than 100M cpuhours on BG/L supercomputers at LLNL, NYBlue, and SDSC. We present parameterizations of the equation of state suitable for input into hydrodynamics models of heavy ion collisions.