Pion decay constants in a strong magnetic field

Decay constants of the charged and neutral pions in magnetic field are considered in the framework of the effective quark-antiquark lagrangian respecting Gell-Mann–Oakes–Renner (GOR) relations at zero field. The $\sqrt{\frac{e_{q}B}{\sigma }}$ dependence is found in strong fields $e_qB\gg \sigma$fortheneutralpion,whilethechargedpionconstantdecreasesas$\sqrt{\frac{\sigma}{e_qB}}$.