Neutrino-induced nucleosynthesis in supernovae

The neutrino-induced reactions in supernova explosions produce some rare odd-odd nuclides. We have made a new time-dependent calculation of the supernova production ratio of the long-lived isomeric state of 180Ta. This time-dependent solution is crucial for understanding the production and survival of this isotope. We find that the explicit time evolution of the synthesis of 180Ta using the available nuclear data avoids the overproduction relative to 138La for a ν-process neutrino temperature of 4 MeV. An unstable isotope 92Nb decays to 92Zr with a half-life of 3.47 × 107 years. We have proposed the ν-process origin for 92Nb. We calculate key neutrino-induced reactions and supernova ν-process. Our calculated result shows that the abundance of 92Nb can be explained by the ν-process.