Non-perturbative thermal QCD at all temperatures: the case of mesonic screening masses

Understand

We present a strategy based on the step-scaling technique to study non-perturbatively thermal QCD up to very high temperatures.

• As a first concrete application, we compute the flavour non-singlet meson screening masses at 12 temperatures covering the range from $T \sim 1$ GeV up to $\sim 160$ GeV in the theory with three massless quarks.
• The calculation is carried out by Monte Carlo simulations on the lattice by considering large spatial extensions in order to have negligible finite volume effects.
• For each temperature we have simulated 3 or 4 values of the lattice spacing, so as to perform the continuum limit extrapolation with confidence at a few permille accuracy.