Probing Majorana neutrino CP phases and masses in neutrino-antineutrino conversion

We propose a new strategy for detecting the CP-violating phases and the effective mass of muon Majorana neutrinos by measuring observables associated with neutrino-antineutrino oscillations in π± decays. Within the generic framework of quantum field theory, we compute the non-factorizable probability for producing a pair of same-charged muons in π± decays as a distinctive signature of νμ−νμ¯ oscillations. We show that an intense neutrino beam through a long baseline experiment is favored for probing the Majorana phases. Using the neutrino-antineutrino oscillation probability reported by MINOS Collaboration, a new stringent bound on the effective muon-neutrino mass is derived.