Anisotropy of the quark anti-quark potential in a magnetic field

We study how the potential of a static quark anti-quark pair for N f = 2 + 1 QCD at the physical point gets modified by the presence of a constant and uniform magnetic field, e ~ B . We observe an anisotropy in the potential, which gets steeper in the directions transverse to e ~ B than in the longitudinal one. By comparing to the case at zero magnetic field, we show that the string tension increases (decreases) in the perpendicular (parallel) direction as a function of j e ~ B j , while the Sommer parameter and the absolute value of the Coulomb coupling display the opposite behavior.