Neutrino-nuclear responses for astro-neutrinos, single beta decays and double beta decays

Abstract

Neutrino–nuclear responses associated with astro-neutrinos, single beta decays and double beta decays are crucial in studies of neutrino properties of interest for astro-particle physics. The present report reviews briefly recent studies of the neutrino–nuclear responses from both experimental and theoretical points of view in order to obtain a consistent understanding of the many facets of the neutrino–nuclear responses. Subjects discussed in this review include (i) experimental studies of neutrino–nuclear responses by means of single beta decays, charge-exchange nuclear reactions, muon- photon- and neutrino–nuclear reactions, and nucleon-transfer reactions, (ii) implications of and discussions on neutrino–nuclear responses for single beta decays, for astro-neutrinos, and for astro-neutrino nucleosynthesis, (iii) theoretical aspects of neutrino–nuclear responses for beta and double beta decays, for nuclear muon capture and for neutrino–nucleus scattering, and (iv) critical discussions on nucleonic and non-nucleonic spin–isospin correlations and renormalization (quenching or enhancement) effects on the axial weak coupling. Remarks are given on perspectives of experimental and theoretical studies of the neutrino–nuclear responses and on future experiments of double beta decays.