Nuclear spin responses for neutrinos and neutrino studies in 100Mo

Abstract

Neutrino masses and mixings, which are key issues of neutrino physics, are studied by investigating low energy neutrinos (λ’s) in nuclei as micro-laboratories. Nuclear spin isospin responses for λ’s are crucial for λ studies in nuclei. Nuclear charge-exchange spinflip reactions are shown to be used for investigating nuclear spin isospin responses. Brief discussions are given on recent studies of nuclear spin isospin responses for low energy λ’s such as solar and supernova λ’s, and for λ’s associated with double beta decays (ββ). 100Mo is found to have large spin isospin responses for these low energy λ’s. Thus spectroscopic studies of ββ decays with a sensitivity of (m λ)≈0.03 eV and realtime studies of low energy solar λ’s are possible by MOON (Mo Observatory of Neutrinos) with multiton 100Mo.