Beta decays with momentum space Majorana spinors
  We construct and apply to beta decays a truly neutral local quantum field that is entirely based upon momentum space Majorana spinors. We make the observation that theory with momentum space Majorana spinors of real C parities is equivalent to Dirac's theory. For imaginary C parities, the neutrino mass can drop from the single beta decay trace and reappear in 0\nu \beta \beta, a curious and in principle experimentally testable signature for a non-trivial impact of Majorana framework in experiments with polarized sources. 
M. Kirchbach, C. Compean, L. Noriega