Nucleosynthesis in Neutrino-Driven Winds in Hypernovae

We investigate the nucleosynthesis in the neutrino-driven winds blown off from a massive proto-neutron star (mPNS) temporarily formed during the collapse of a star. Such mPNSs would be formed in hypernovae. We construct steady and spherically symmetric wind solutions. We set large neutrino luminosities of and average energies of electron neutrinos and antineutrinos in the ranges of and based on a recent numerical relativity simulation. The wind solutions indicate a temperature-decrease timescale much shorter than that of the winds from ordinary PNSs, and, depending on , the winds can be both neutron-rich and proton-rich. In the neutron-rich wind, the r -process occurs and the abundance distribution of a fiducial wind model of the mPNS gives an approximate agreement with the abundance pattern of metal-poor weak r star HD 122563, although the third-peak elements are produced only when the energy is much larger than the energy. In the proton-rich wind, the strong -process occurs and nuclides are synthesized. The synthesized nuclei can be neutron-rich in some cases because the large neutrino luminosity of the mPNS supplies a sufficient amount of neutrons.