CP Violation in Predictive Neutrino Mass Structures

Abstract

We study the CP violation effects from two types of neutrino mass matrices with (i) $(M_{\nu }{)}_{ee}=0$, and (ii) $(M_{\nu }{)}_{ee}=(M_{\nu }{)}_{e\mu }=0$, which can be realized by the high dimensional lepton number violating operators ${\bar{\ell }}_R^c{\gamma }^{\mu }{L}_L(D_{\mu }\Phi ){\Phi }^2$ and ${\bar{\ell }}_R^c{l}_R(D_{\mu }\Phi {)}^2{\Phi }^2$, respectively. In (i), the neutrino mass spectrum is in the normal ordering with the lightest neutrino mass within the range $0.002\mathrm{eV}\lesssim m_0\lesssim 0.007\mathrm{eV}$. Furthermore, for a given value of $m_0$, there are two solutions for the two Majorana phases ${\alpha }_{21}$ and ${\alpha }_{31}$, whereas the Dirac phase $\delta$ is arbitrary. For (ii), the parameters of $m_0$, $\delta$, ${\alpha }_{21}$, and ${\alpha }_{31}$ can be completely determined. We calculate the CP violating asymmetries in neutrino-antineutrino oscillations for both mass textures of (i) and (ii), which are closely related to the CP violating Majorana phases.

Comments: 17 pages, 4 figures, revised version accepted by EPJC