Equation of State of Nf=3 QCD up to the electroweak scale

by Dr Matteo Bresciani (TCD Dublin)

Monday 24 Nov 2025, 13:15 → 14:15 Europe/Berlin

https://hu-berlin.zoom-x.de/j/61683219986?pwd=LUqqV9dJNgLLRiasDzvbWYCwl7pNVm.1 (Zoom)

We present the non-perturbative determination of the Equation of State of QCD with three massless flavours in the temperature range between 3 GeV and 165 GeV. The continuum-extrapolated results for the entropy density -- our primary observable -- have a precision of $1\%$ or better, and are well described by a linear behaviour in the strong coupling squared, pointing to the Stefan-Boltzmann limit. The comparison with the perturbative prediction shows that contributions beyond the known ones, including non-perturbative effects, are relevant at all temperatures up to the electroweak scale. This calculation is made feasible by a new strategy based on defining  the lines of constant physics through the running of a renormalized coupling defined non-perturbatively in finite-volume, and by considering thermal QCD with shifted boundary conditions. This strategy is general and can be readily applied to the case of QCD with five massive flavours.