Lepton flavor changing in neutrinoless decays
Laboratoire de Physique Théorique et Hautes Energies, Paris CNRS, Université P. et M. Curie, Université D. Diderot
Received: 29 October 1998 / Published online: 11 March 1999
Neutrino oscillations, as recently reported by the Super-Kamiokande collaboration, imply that lepton numbers could be violated, and are some typical examples. We point out that in these neutrinoless modes, the GIM cancelation is much milder with only a logarithmic behavior where mj, k are the neutrino masses. This is in sharp contrast with the vanishingly small amplitude strongly suppressed by the quadratic power . In comparison with the hopelessly small branching ratio B, the B could be larger than 10-14. The latter mode, if measurable, could give one more constraint to the lepton mixing angle and the neutrino mass ratio mj/mk, and therefore is complementary to neutrino oscillation experiments.