Majorana phases in neutrino-antineutrino oscillations

Abstract

If the massive neutrinos are Majorana particles, neutrinoless double beta ($0νββ$) decay experiments are not enough to determine the Majorana phases. We carry out a systematic study of CP violation in neutrino-antineutrino oscillations. In these processes, CP-conserving parts involve six independent $0νββ$-like mass terms $\langle m\rangle_{αβ}$ and CP-violating parts are associated with nine independent Jarlskog-like parameters ${\cal V}^{ij}_{αβ}$ (for $α, β= e, μ, τ$ and $i, j = 1, 2,3$). With the help of current neutrino oscillation data, we illustrate the salient features of six independent CP-violating asymmetries between $ν_α\to \barν_β$ and $\barν_α\to ν_β$ oscillations.