Confining and chiral properties of QCD in extremely strong magnetic fields

We investigate, by numerical lattice simulations, the static quark-antiquark potential, the flux tube properties and the chiral condensate for Nf=2+1 QCD with physical quark masses in the presence of strong magnetic fields, going up to eB=9 GeV2, with continuum extrapolated results. The string tension for quark-antiquark separations longitudinal to the magnetic field is suppressed by 1 order of magnitude at the largest explored magnetic field with respect to its value at zero magnetic background, but is still nonvanishing; in the transverse direction, instead, the string tension is enhanced but seems to reach a saturation at around 50% of its value at B=0. The flux tube shows a consistent suppression/enhancement of the overall amplitude, with mild modifications of its profile. Finally, we observe magnetic catalysis in the whole range of explored fields with a behavior compatible with a lowest Landau level approximation, in particular with a linear dependence of the chiral condensate on B which is in agreement, within errors, with that already observed for eB∼1 GeV2.