Neutrino-induced Charged Current Electroweak Transition from Lambda-to Sigma-hyperon

Abstract

In this paper, we present a fully relativistic description of charged current (CC) neutrino-hyperon scattering process near and above the threshold energy. The main focuses were the evaluations of the invariant matrix element (IME) and differential cross section (DCS) within the framework of the Glashow-Weinberg-Salam (GWS) model. By employing the standard model the exact expression of leptonic tensor in semi-leptonic electroweak interactions was determined. However, the hadronic tensor involves a vertex which is not fully understood by the electroweak theory since hyperons are composite particles. As such, hadronic vertex was parameterized by three unknown form factors to account for the effects of strong interaction. Then the unknown form factors were determined in the framework of the Cabibbo V-A theory and SU(3) symmetry. The angular distributions show that the DCS attains its peak near the forward scattering angles, whereas the energy distributions of the DCS indicate that dominate contribution comes from incident energies near the threshold energy. Based on our results, the quasielastic CC process under study can be considered as an intermediate energy phenomena as its DCS tends to vanish in high energy region.