Neutrino reactions on the deuteron

Abstract

The cross sections for the $\ensuremath{\nu}\ensuremath{-}d$ and $\overline{\ensuremath{\nu}}\ensuremath{-}d$ reactions are calculated for incident energy up to ${E}_{\ensuremath{\nu}}=170 \mathrm{MeV}$ with the use of a phenomenological Lagrangian approach. We assess and improve the reliability of the employed calculational method by examining the dependence of the results on various input and approximations that go into the calculation. The main points of improvement over the existing work are (1) use of the ``modern'' $\mathrm{NN}$ potentials, (2) use of the more accurate nucleon weak-interaction form factors, and (3) monitoring the strength of a vertex that governs the exchange-current contribution, with the use of data on the related process, $n+\stackrel{\ensuremath{\rightarrow}}{p}d+\ensuremath{\gamma}.$ In addition to the total cross sections, we present various differential cross sections that are expected to be useful for the SNO and other experiments. In the low-energy regime relevant to the solar neutrinos, the newly calculated total cross sections essentially agree with the existing literature values. The origins of slight differences found for higher energies are discussed. The ratio between the neutral-current and charged-current reaction cross sections is found to be extremely stable against any variations in the input of our calculation.