Lattice QCD equation of state : improving the differential method

TL;DR

This paper introduces an improved differential method for calculating the QCD equation of state from lattice simulations, ensuring positive pressure across all temperatures and providing detailed thermodynamic quantities in quenched QCD.

Contribution

The authors develop a novel variation of the differential method that guarantees positive pressure and apply it to lattice QCD, extending the temperature range and improving accuracy.

Findings

Positive pressure obtained across all temperatures including the transition region

Pressure, energy density, entropy density, specific heat, and speed of sound computed for 0.9 < T/Tc < 3

Results compared favorably with dimensional reduction and conformal theories at high temperature

Abstract

We propose an improvement of the differential method for the computation of the equation of state of QCD from lattice simulations. In contrast to the earlier differential method our technique yields positive pressure for all temperatures including in the transition region. Employing it on temporal lattices of 8, 10 and 12 sites and by extrapolating to zero lattice spacing we obtained the pressure, energy density, entropy density, specific heat and speed of sound in quenched QCD for 0.9 < T/Tc < 3. A comparison of our results is made with those from the dimensional reduction approach and a conformal symmetric theory at high-temperature.