Towards the QCD equation of state at the physical point using Wilson fermion

Abstract

We study the (2+1)-flavor QCD at nonzero temperatures using nonperturbatively improved Wilson quarks of the physical masses by the fixed scale approach. We perform physical point simulations at finite temperatures with the coupling parameters which were adopted by the PACS-CS Collaboration in their studies using the reweighting technique. Zero temperature values are obtained on the PACS-CS configurations which are open to the public on the ILDG/JLDG. Finite temperature configurations are generated with the RHMC algorithm. The lattice sizes are 32 3 ×N t with N t = 14, 13, · · ·, 4 which correspond to T ≈ 160-550 MeV. We present results of some basic observables at these temperatures and the status of our calculation of the equation of state.

On the strength of the U A (1) anomaly at the chiral phase transition in N f = 2 QCD

“…Like other studies in the literature we see that T C decreases with the quark mass [26][27][28][29][30][31][32][33][34][35][36], which is a general feature, persisting even when dynamical heavy quarks are included (e.g. [14,15]).…”

“…There is plenty of evidence that the physical quark mass configuration realised in nature is in the crossover region. Early results based on the staggered fermion discretisation [8,9] have been confirmed by domain wall fermions [10,11] and simulations with Wilson fermions are approaching the physical point as well [12][13][14][15]. The critical line separating the first order chiral transitions from the crossover region, the chiral critical line, has been mapped out on coarse lattices and is in the Z(2) universality class of the 3d Ising model [16,17].…”

Latent heat at the first order phase transition point of SU(3) gauge theory

“…This may help calculation of the equation of state in full QCD, where a precise evaluation of (ǫ − 3p)/T 4 needed in the integral method is quite costly at low temperatures (large N t ). The derivative method is an attractive choice also in the fixed scale approach [27,28].…”