Neutrino and antineutrino quasielastic interactions with nuclei

We investigate the interaction of neutrinos and antineutrinos with nuclei. We explore, in particular, the role played by multinucleon excitations, which can contaminate the quasielastic cross section. For neutrinos the multinucleon term produces a sizable increase in the quasielastic cross section. Part of the effect arises from tensor correlations. For antineutrinos this influence is smaller, owing to the axial-vector interference, which increases the relative importance of the terms that are not affected by these multinucleon excitations.