Gamow-Teller Strengths of the Inverse-Beta Transition 176Yb --> 176Lu   for Spectroscopy of Proton-Proton and other sub-MeV Solar Neutrinos
  Discrete Gamow-Teller (GT) transitions, 176Yb-->176Lu at low excitation energies have been measured via the (3He,t) reaction at 450 MeV and at 0 degrees. For 176Yb, two low-lying states are observed, setting low thresholds Q(neutrino)=301 and 445 keV for neutrino capture. Capture rates estimated from the measured GT strengths, the simple two-state excitation structure, and the low Q(neutrino) in Yb--Lu indicate that Yb-based neutrino-detectors are well suited for a direct measurement of the complete sub-MeV solar electron-neutrino spectrum (including pp neutrinos) where definitive effects of flavor conversion are expected. 
M. Fujiwara (1,2), H. Akimune (3), A.M. van den Berg (4), M. Cribier   (5), I. Daito(6), H. Ejiri(1), H. Fujimura(1), Y. Fuj...