40Ti β decay and the neutrino capture cross section of 40Ar

Abstract

40Ti β decay was studied at GANIL using the LISE3 spectrometer. A decay scheme was deduced from twenty-one observed β-delayed proton transitions feeding the ground and first excited states of 39Ca. The 40Ti half-life was found to be 51.7(6) ms. These results imply that the ICARUS 40Ar detector has an effective absorption cross section for 8B solar neutrinos of 14.5(4) × 10−43 cm2; 73% of the total cross section arises from Gamow-Teller transitions that were neglected in early estimates of the ICARUS efficiency.