Speaker
Description
In this talk, I will present our recent non-perturbative determination of the Equation of State of QCD with three flavours, using the lattice regularization of the theory. Our primary observable is the entropy density, that we determine in the temperature range between 3 GeV and 165 GeV with final sub-percent statistical precision on the continuum-extrapolated results. The entropy density shows a linear behaviour in the strong coupling squared pointing to the Stefan-Boltzmann limit at infinite temperature. It is also compatible with the known perturbative expansion supplemented by higher order terms, accounting for non-perturbative contributions. This parametrization describes well our data and those available in the literature at lower temperatures, down to 500 MeV. Pressure and energy density can be derived as well using standard thermodynamic relations. The strategy for this calculation can be extended to QCD with four or five flavours, opening the way to a non-perturbative determination of the Equation of State in full QCD.