Weak currents in nondiagonal leptonic processes

Abstract

Nondiagonal leptonic processes are studied on the basis of neutral (NC) and charged (CC) weak current interactions. NC and CC descriptions of recoil electron spectra upon the elastic scattering of neutral (anti)leptons, including arbitrary vector and axial-vector current constants that can be real and complex or purely imaginary, are presented. Based on the NC description, the spectrum of muons originating upon the inelastic scattering of a muonic neutrino by a polarized target electron, the total cross section of this process and neutron conversion of an electron–muon pair, as well as the charged and neutral components of the electron spectrum emitted in muon decay are obtained. The possibility of forbidden nondiagonal neutral electron–muon currents emerging in these processes is analyzed.