Electromagnetic properties of neutrinos in the left-right model

Abstract

Within the left-right model contributions to the neutrino dipole magnetic moments coming from the charged gauge bosons ${W}_{1,2}^{\ifmmode\pm\else\textpm\fi{}}$ and the singly charged Higgs bosons ${\stackrel{\texttildelow{}}{\ensuremath{\delta}}}^{(\ifmmode\pm\else\textpm\fi{})}$ are considered. Calculations show that the Higgs sector contributions to the dipole magnetic moments could exceed the contributions caused by the charged gauge bosons. The resonance transitions in the light left-handed neutrino beam moving in a matter and a magnetic field are investigated in two flavor approximations. Analysis leads to the conclusion that the structure of the heavy neutrino sector admits only three possibilities: (i) the light-heavy neutrino mixing angles ${\ensuremath{\theta}}_{ii}$ ($i=1,2$) are arbitrary but equal each other whereas the heavy neutrino masses are quasidegenerate; (ii) the heavy neutrino masses are hierarchical (${m}_{{N}_{1}}<{m}_{{N}_{2}}$) while the angles ${\ensuremath{\theta}}_{ii}$ are equal to zero; (iii) the light-heavy mixing angles ${\ensuremath{\theta}}_{ii}$ are equal to each other and the heavy-heavy neutrino mixing is maximal.