The non-equivalence of Weyl and Majorana
neutrinos with standard-model gauge interactions
Max-Planck-Institut für Physik (Werner-Heisenberg-Institut)
Föhringer Ring 6
D-80805 München, Germany
It is shown that a Majorana neutrino with identical
phenomenology as a standard-model
Weyl neutrino obeys a Lagrangian
different by a factor
in the weak-interaction term
from the one that follows from the standard
model. Assuming that the standard model does
in good approximation for the weak interactions of
a Majorana neutrino e.g. a charged-current production
cross section a factor 2 larger
than the observed one is predicted.
From this it is concluded that the neutrino is not of Majorana type.
This conclusion does not
forbid the possible existence
of a Weyl neutrino with a Majorana mass term
and ensuing lepton-number violating phenomena (like
e.g. neutrino-less double beta decay).
The paper is not in contradiction with any published
literature, because it analyses
the formal proof of equivalence between Weyl and Majorana
neutrino for the first time under the assumption that
the standard model is quantitatively
correct for the weak interactions of the neutrino.