出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The astrophysical origin of the r-process nuclei is still unknown. Even the most promising scenario,
the neutrino-driven winds from a nascent neutron star, encounters severe difficulties in obtaining
requisite entropy and short dynamic timescale for the r-process. In this study, the effect of
anisotropy in neutrino emission is examined with semi-analytic neutrino-driven wind models. It
is shown that the neutrino heating rate from neutrino-antineutrino pair annihilation into electronpositron
pairs can significantly enhance owing to the anisotropy and play a dominant role for the
heating of wind material. A factor of five increase in the effective neutrino luminosity results in
50% higher entropy and a factor of ten shorter dynamic timescale owing to this enhanced neutrino
heating. The nucleosynthesis calculations show that this brings the weak r-process model to the
main r-process model, producing the third abundance peak (A = 195) and beyond.
