Equation of state and QCD transition at finite temperature
Abstract
We calculate the equation of state in 2+1 flavor QCD at finite temperature with physical strange quark mass and almost physical light quark masses using lattices with temporal extent N_{τ}=8. Calculations have been performed with two different improved staggered fermion actions, the asqtad and p4 actions. Overall, we find good agreement between results obtained with these two O(a^{2}) improved staggered fermion discretization schemes. A comparison with earlier calculations on coarser lattices is performed to quantify systematic errors in current studies of the equation of state. We also present results for observables that are sensitive to deconfining and chiral aspects of the QCD transition on N_{τ}=6 and 8 lattices. We find that deconfinement and chiral symmetry restoration happen in the same narrow temperature interval. In an appendix we present a simple parametrization of the equation of state that can easily be used in hydrodynamic model calculations. In this parametrization we include an estimate of current uncertainties in the lattice calculations which arise from cutoff and quark mass effects.
 Publication:

Physical Review D
 Pub Date:
 July 2009
 DOI:
 10.1103/PhysRevD.80.014504
 arXiv:
 arXiv:0903.4379
 Bibcode:
 2009PhRvD..80a4504B
 Keywords:

 11.15.Ha;
 12.38.Gc;
 Lattice gauge theory;
 Lattice QCD calculations;
 High Energy Physics  Lattice;
 High Energy Physics  Phenomenology;
 Nuclear Theory
 EPrint:
 31 pages, 24 EPSfigures