EXCHANGE CURRENT CORRECTIONS TO NEUTRINO-NUCLEUS SCATTERING .1. NUCLEAR-MATTER

Relativistic exchange current corrections to the impulse approximation in low and intermediate energy neutrino-nucleus scattering are presen ted assuming nonvanishing strange quark form factors for constituent n ucleons. Two-body exchange current operators which treat all SU(3) vec tor and axial currents on an equal footing are constructed by generali zing the soft-pion dominance method of Chemtob and Rho. For charged cu rrent reactions, exchange current corrections can reduce the impulse a pproximation results by 5 to 10 % depending on the nuclear density. A finite strange quark form factor may change the total cross section fo r neutral current scattering by 20% while exchange current corrections are found to be sensitive to the nuclear density. Implications on the current LSND experiment to extract the strange quark axial form facto r of the nucleon are discussed.