The HotQCD Equation of State

TL;DR

This paper reports on lattice QCD calculations of the equation of state at zero baryon density, providing parameterizations for hydrodynamic models in heavy ion collision research.

Contribution

The study offers new lattice QCD results for the QCD equation of state using improved staggered fermions and extensive computational resources, aiding hydrodynamic modeling.

Findings

Calculated QCD equation of state on a $32^3 imes 8$ lattice.

Provided parameterizations for hydrodynamic simulations.

Performed over 100 million CPU-hours on supercomputers.

Abstract

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 $32^3 \times 8$ with $m_l = 0.1 m_s$ (corresponding to a pion mass of $\sim$220 MeV) using two improved staggered fermion actions, p4 and asqtad. C alculations were performed along lines of constant physics using more than 100M cpu-hours on BG/L supercomputers at LLNL, NYBlue, and SDSC. We present paramete rizations of the equation of state suitable for input into hydrodynamics models of heavy ion collisions.