Neutrino-nucleus reactions based on new shell model Hamiltonians

A new shell model Hamiltonian for p-shell nuclei which properly takes into account important roles of spin-isospin interactions is used to obtain cross sections of neutrino-C12 reactions induced by decay-at-rest neutrinos as well as supernova neutrinos. Branching ratios to various decay channels are calculated by the Hauser-Feshbach theory. Neutrino-He4 reactions are also investigated by using recent shell model Hamiltonians. The reaction cross sections are found to be enhanced for both C12 and He4 compared with previous calculations. As an interesting consequence of this, a possible enhancement of the production yields of light elements, Li7 and B11, during supernova explosions is pointed out.