Spin light in neutrino transition between different mass states

The spin light of neutrino is considered in the process of a neutrino radiative transition between two different mass states in presence of medium. By this study we investigate the influence of background matter on the initial and final neutrino states in the process of massive Dirac neutrino decay due to the non-zero transition magnetic moment. We derive corresponding corrections to the total width of the process over the matter density in most important for applications cases.