High-resolution 100Mo(3He,t)100Tc charge-exchange experiment and the impact on double-β decays and neutrino charged-current reactions

The Gamow-Teller (GT) strength distribution has been investigated in a high-resolution (3He,t) charge-exchange experiment on the double-beta (ββ) decaying nucleus 100Mo. The experiment was carried out at the Osaka University Research Center for Nuclear Physics (RCNP) with a 420 MeV incident 3He beam and the Grand Raiden magnetic spectrometer. A final-state energy resolution of 33 keV was achieved. It was found that nearly the entire low-energy (up to ≈4 MeV) GT− strength is concentrated in the ground-state transition to 100Tc, which is interpreted as a result of the particular neutron and proton sub-shell occupancies. The impact on the matrix elements for the two-neutrino double-beta (2νββ) decay and the use of 100Mo as a neutrino detection material is discussed.