Neutrino-nucleus reaction cross sections for light element synthesis in supernova explosions

Yoshida, Takashi*; Suzuki, Toshio*; Chiba, Satoshi; Kajino, Toshitaka*; Yokomakura, Hidekazu*; Kimura, Keiichi*; Takamura, Akira*; Hartmann, D.*

The neutrino-nucleus reaction cross sections of He and C are evaluated using new shell model Hamiltonians. Branching ratios of various decay channels are calculated to evaluate the yields of Li, Be, and B produced through the -process in supernova explosions. The new cross sections enhance the yields of Li and B produced during the supernova explosion of a 16.2 M star model compared to our previous study by factors of 1.3 and 1.2, respectively. On the other hand, the yield of B decreases by a factor of three. The yields of Li, Be, and the radioactive nucleus Be are found at a level of 10 to 11 M. The temperature of - and -neutrinos inferred from the supernova contribution of B in Galactic chemical evolution models is constrained to be in the range 4.5 MeV to 6.4 MeV. The increase in the Li and B yields due to neutrino oscillations is demonstrated with the new cross sections.