Topological susceptibility and fourth cumulant in a uniform magnetic field

We study the topological susceptibility and fourth cumulant of QCD vacuum in a background magnetic field (H) using three-flavor chiral perturbation theory (χPT) for arbitrary quark masses n-flavor χPT with degenerate masses. find that enhancement by relative to H=0 value is larger compared two-flavor χPT. Additionally, comparing cumulant, we its suppression comparable fields, eH≲0.8mπ2, weaker fields beginning at significantly lower critical also quarks greater weak pushed out both two