Nambu-Goldstone mesons in strong magnetic field

We study the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ q\overline{q} $\end{document} structure embedded in chiral mesons in response to external magnetic fields (m.f.), using the chiral Lagrangian with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ q\overline{q} $\end{document} degrees of freedom derived earlier. We show that GMOR relations hold true for neutral chiral mesons, while they are violated for the charged ones for eB > σ = 0.2GeV2. The standard chiral perturbation theory also fails in this region. Masses of π+ and π0 mesons are calculated and compared to lattice data.