Creation of electron-positron pairs Ьу а massive photon iп magпetic field

We examine the production of $e^{+}$ $e^{-}$ pairs by a massive photon and the annihilation of $e^{+}$ $e^{-}$ pairs with the formation of a massive photon in13 an ultrastrong magnetic field $H≥ B_{0}= 4.41∙10^{13}G$. We obtain the conditions under which the external magnetic field begins to exert a substantial effect on these processes.