General Local Interactions and Tests ofV−ATheory in Neutrino Scattering Processes

Abstract

Neutrino scattering processes are studied in the framework of general local current-current interaction. The scattering amplitudes for such processes are expressed in a simple factorized form in terms of helicity form factors for the current vertex functions. These expressions explicitly display the full kinematic content of the local current-current interaction and are used as the basis for a systematic study of possible ways to test the $V-A$ structure of the weak current in high-energy neutrino scattering processes. A direct test in an "inclusive experiment" consists of measuring the outgoing lepton polarization. Alternative tests from angular and spin correlations are possible only in "exclusive experiments." Several examples of this latter type of experiment are given: (i) pure lepton scattering processes, (ii) neutrino scattering off spin-zero (nuclei) targets, (iii) quasi-elastic scattering off polarized-nucleon targets, (iv) quasi-elastic hyperon production (decay asymmetry), and (v) single-pion production in the $N^{*}$ region.