The ν-Process in the Light of an Improved Understanding of Supernova Neutrino Spectra

We study the neutrino-induced production of nuclides in explosive supernova nucleosynthesis for progenitor stars with solar metallicity including neutrino-nucleus reactions for all nuclei with charge numbers Z < 76, with average neutrino energies in agreement with modern supernova simulations. Considering progenitors with initial main sequence masses between 13 M ⊙ and 30 M ⊙, we find a significant production of 11B, 138La, and 180Ta by neutrino nucleosynthesis, despite the significantly reduced neutrino energies. The production of 19F turns out to be more sensitive to the progenitor mass and structure than to the ν-process. With our complete set of cross sections we have identified the effects of the ν-process on several stable nuclei including 33S, 40Ar, 41K, 59Co, and 113In at the 10% level. Neutrino-induced reactions contribute to a similar extent to the production of radioactive 26Al and increase the yield of 22Na by 50%. Future γ-ray astronomy missions may reach the sensitivity at which the contribution from the ν-process becomes relevant. We find that the production of 22Na by the ν-process could explain the Ne-E(L) component of meteoritic graphite grains. The ν-process enhances the yield of 36Cl and we point out that the resulting 36Cl/35Cl ratio is in agreement with the values inferred for the early solar system. Our extended set of neutrino-nucleus interactions also allows us to exclude any further effects of the ν-process on stable nuclei and to quantify the effects on numerous, hitherto unconsidered radioactive nuclei, e.g., 36Cl, 72As, 84Rb, and 88Y.