# Quark Matter 2017

Feb 5 – 11, 2017
Hyatt Regency Chicago
America/Chicago timezone

## The QCD Equation of State and critical end-point estimates at $\mathbf{6}^{th}$ order in chemical potentials

Feb 7, 2017, 3:20 PM
20m
Regency A

### Regency A

Oral QCD at High Temperature

### Speaker

Sayantan Sharma (BNL)

### Description

The QCD Equation of State (EoS) is fundamental for our understanding of the properties
of strong-interaction matter at non-zero temperature and density. In view of the
upcoming Beam Energy Scan II program at RHIC, it is important to gain control
over the EoS in the entire range of chemical potentials ($\mu_B$) accessible at
RHIC, $0\le \mu_B/T \le 3$. This will provide crucial input for the hydrodynamic
modeling of hot and dense matter and will allow to clarify whether or not a
critical end-point exists in this parameter range.

We present results for the QCD Equation of State at non-zero chemical potentials
corresponding to the conserved charges in QCD using Taylor expansion upto $6^{th}$ order
in the baryon number, electric charge and strangeness chemical potentials. The latter
two are constrained by strangeness neutrality and a fixed electric charge to
baryon number ratio. In our calculations, we use the Highly Improved Staggered Quarks
(HISQ) discretization scheme at different values of the lattice spacings to
control lattice cut-off effects. The light and strange quark masses are
adjusted to reproduce physical values of pion and kaon masses. Furthermore we calculate the
pressure along lines of constant energy density, which serve as proxies for the
freeze-out conditions and discuss their dependence on $\mu_B$, which is necessary for
hydrodynamic modeling near freezeout.

We also provide an estimate of the radius of convergence of the Taylor series from the $6$th order
coefficients which gives a new constraint on the location of the critical end-point
in the $T$-$\mu_B$ plane of the QCD phase diagram.

Preferred Track QCD at High Temperature Other