The QCD Equation of State to $\mathcal{O}({\mu }_B^4)$ from Lattice QCD

Abstract

We present first results from a first-principles calculation of the QCD equation of state to $\mathcal{O}({\mu }_B^4)$, where ${\mu }_B$ is the baryon chemical potential. We find that second-order corrections are sufficient for a large part of the freeze-out temperature and baryon chemical potential range achieved by the RHIC beam energy scan. Nevertheless, higher-order corrections are necessary to extend the validity of the equation of state down to beam energies $s_{NN}^{1/2}\sim 20$ GeV.

Comments: 4 pages, 11 figures; contribution to the proceedings of Quark Matter 2014