NEUTRINO CAPTURE CROSS-SECTIONS FOR AR-40 AND BETA-DECAY OF TI-40

Shell-model calculations of solar neutrino absorption cross sections f or Ar-40, the proposed component of the ICARUS detector, are presented . It is found that low-lying Gamow-Teller transitions lead to a signif icant enhancement of the absorption rate over that expected from the F ermi transition between the isobaric analog states, leading to an over all absorption cross section for B-8 neutrinos of (11.5 +/- 0.7) x 10( -43) Cm-2 or a total expected rate of 6.7 + 2.5 SNU. We also note that the pertinent Gamow-Teller transitions in Ar-40, experimentally acces sible from the P-decay of the mirror nucleus Ti-40. Predictions for th e branching ratios to states in (SC)-S-40 are presented, and the theor etical halflife of 55 +/- 5 ms is found to be in good agreement with t he experimental value of 56(-12)(+18) ms.