RESONANT NEUTRINO SPIN-FLAVOR PRECESSION AND SUPERNOVA NUCLEOSYNTHESIS AND DYNAMICS

We discuss the effects of resonant spin-flavor precession (RSFP) of Ma jorana neutrinos on heavy element nucleosynthesis in neutrino-heated s upernova ejecta and the dynamics of supernovae. In assessing the effec ts of RSFP, we explicitly include matter-enhanced (MSW) resonant neutr ino flavor conversion effects where appropriate. We point out that for plausible ranges of neutrino magnetic moments and protoneutron star m agnetic fields, spin-flavor conversion of nu(tau) (or nu(mu)) with a c osmologically significant mass (1-100 eV) into a light <(nu)over bar ( e)> could lead to an enhanced neutron excess in neutrino-heated supern ova ejecta. This could be beneficial for models of r-process nucleosyn thesis associated with late-time neutrino-heated ejecta from supernova e. Similar spin-flavor conversion of neutrinos at earlier epochs could lead to an increased shock reheating rate and, concomitantly, a large r supernova explosion energy. We show, however, that such increased ne utrino heating likely will be accompanied by an enhanced neutron exces s which could exacerbate the problem of the overproduction of the neut ron number N = 50 nuclei in the supernova ejecta from this stage. In a ll of these scenarios, the average <(nu)over bar (e)> energy will be i ncreased over those predicted by supernova models with no neutrino mix ings. This may allow the SN 1987A data to constrain RSFP-based schemes .