We provide numerical evidence that the thermal QCD crossover turns into a first order transition in the presence of large enough magnetic background fields. The critical endpoint is found to be located between eB=4 GeV2 (where the pseudocritical temperature is Tc=(98±3) MeV) and eB=9 GeV2 (where the critical temperature is Tc=(63±5) MeV). Results are based on the analysis of quark condensates and number susceptibilities, determined by lattice simulations of Nf=2+1 QCD at the physical point, discretized with three different lattice spacings, a=0.114,0.086 and 0.057 fm, via rooted stout staggered fermions and a Symanzik tree level improved pure gauge action. We also present preliminary results regarding the confining properties of the thermal theory, suggesting that they could change drastically going across the phase transition
@article{arxiv.2111.11237,
title = {Phase diagram of QCD in a magnetic background},
author = {Massimo D'Elia and Lorenzo Maio and Francesco Sanfilippo and Alfredo Stanzione},
journal= {arXiv preprint arXiv:2111.11237},
year = {2022}
}