Signals for Strange Quark Contributions to the Neutrino (Antineutrino) Scattering in Quasi-Elastic Region

Abstract

Strange quark contributions to elastic neutrino-nucleon scattering and neutrino-nucleus scattering for C-12 target in quasi-elastic region are investigated on the incident energy of 500 MeV within the framework of a relativistic single particle model. For the neutrino-nucleus scattering, the effects of final state interaction for the knocked-out nucleon are included by a relativistic optical potential. In the cross sections for neutrino-nucleus scattering we found some cancellations of the strange quark contributions in the knocked-out proton and neutron process. Consequently, the asymmetries between the incident neutrino and antineutrino, which are given by the ratio of neutral current to charged current, and a difference between the asymmetries are shown to be more feasible quantities for the strangeness effects. In order to explicitly display the importance of such cancellations, results of the exclusive reaction O-16(nu, nu'p) are additionally presented for detecting the strangeness effects.