Abstract
Neutrinos may be pseudo-Dirac states, such that each generation is actually composed of two maximally mixed Majorana neutrinos separated by a tiny mass difference. The usual active neutrino oscillation phenomenology would be unaltered if the pseudo-Dirac splittings are ; in addition, neutrinoless double beta decay would be highly suppressed. However, it may be possible to distinguish pseudo-Dirac from Dirac neutrinos using high-energy astrophysical neutrinos. By measuring flavor ratios as a function of , mass-squared differences down to can be reached. We comment on the possibility of probing cosmological parameters with neutrinos.
- Received 10 July 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.011101
©2004 American Physical Society