Neutrino (antineutrino) disintegration of the deuteron and the structure of the neutral weak current

Abstract

We study the neutrino (antineutrino) disintegration of the deuteron with the view of determining the isospin and Lorentz character of the neutral weak current. Neutrino-induced transition rates between the ${}_{}{}^3{}_{}{}^{}S\to {}_{}{}^1{}_{}{}^{}S$, ${}_{}{}^3{}_{}{}^{}S\to {}_{}{}^1{}_{}{}^{}P$, and ${}_{}{}^3{}_{}{}^{}S\to {}_{}{}^3{}_{}{}^{}P$ of the neutron-proton system are derived for the most general form of the neutral weak current, valid up to intermediate neutrino energies (0-500 MeV). Explicit results are presented for the Weinberg-Salam model, the Bég-Zee model, and the case of an isoscalar neutral weak current. It is argued that this process can be, in principle, used to distinguish between the various assignments of the Lorentz and isospin properties of the hadronic neutral weak current.