Revealing neutrino nature and CPT violation with decoherence effects

We study decoherence effects on mixing among three generations of neutrinos. We show that in presence of a non-diagonal dissipation matrix, both Dirac and Majorana neutrinos can violate the CPT symmetry and the oscillation formulae depend on the parametrization of the mixing matrix. We reveal the CP violation in the transitions preserving the flavor, for a certain form of the dissipator. In particular, for such dissipators, the CP violation affects all the transitions in the case of Majorana neutrinos, unlike Dirac neutrinos which still preserve the CP symmetry in one of the transitions flavor preserving. The precise form of the dissipation matrix is not known a-priori as it depends on the nature of the phenomenon that originates it. However, our theoretical results show that decoherence effects, if exist for neutrinos, could allow to reveal the neutrino nature and to test fundamental symmetries.