Probing nucleon strangeness with neutrinos: Nuclear model dependences

The extraction of the nucleon close-quote s strangeness axial charge Δs from inclusive, quasielastic neutral current neutrino cross sections is studied within the framework of the plane-wave impulse approximation. We find that the value of Δs can depend significantly on the choice of nuclear model used in analyzing the quasielastic cross section. This model dependence may be reduced by one order of magnitude when Δs is extracted from the ratio of total proton to neutron yields. We apply this analysis to the interpretation of low-energy neutrino cross sections and arrive at a nuclear theory uncertainty of ±0.03 on the value of Δs expected to be determined from the ratio of proton and neutron yields measured by the LSND Collaboration. This error compares favorably with estimates of the SU(3)-breaking uncertainty in the value of Δs extracted from inclusive, polarized deep-inelastic structure function measurements. We also point out several general features of the quasielastic neutral current neutrino cross section and compare them with the analogous features in inclusive, quasielastic electron scattering. copyright 1996 The American Physical Society