Stability of Neutrino Mass Degeneracy

Abstract

Two neutrinos of Majorana masses $m_{1,2}$ with mixing angle $\theta$ are unstable against radiative corrections in the limit $m_1=m_2$, but are stable for $m_1=-m_2$ (i.e. opposite CP eigenstates) with $\theta =45^{\circ }$ which corresponds to an additional symmetry.

Comments: 7 pages, no figure, one reference added