Speaker
Description
We present results from a calculation of the QCD equation of state up
to the sixth order in the baryon, strangeness and electric charge
chemical potentials. As the results depend on three independent chemical
potential, we consider various cases to parametrize the strangeness
and electric charge chemical potentials as a function of the baryon
chemical potential and temperature. Among these, the conditions met in
heavy ion collision are best reproduced by enforcing strangeness
neutrality and a constant baryon number to electric charge ratio. We
will further discuss how cumulant rations of conserved charge
fluctuations that are available in both, lattice QCD simulations and
heavy ion experiments, can be used to determine freeze-out parameter of
the experiment including the freeze-out curvature.
The presented results are based on lattice calculations performed with
the Highly Improved Staggered Quark action (HISQ) in the temperature
range 140 MeV < T < 330 MeV, with lattice sizes $24^3 \times 6$,
$32^3 \times 8$, $48^3\times 12$ and $16^3\times 16$. The strange
quark mass is tuned to its physical value and we use ratios of strange
to light quark masses including $m_s/m_l = 20$ and 27, which in the
continuum corresponds to a pion masses of 160 and 140 MeV.
