Supernova Nucleosynthesis and the Physics of Neutrino Oscillation

摘要

We studied the explosive nucleosynthesis in core-collapse supernovae and found that several isotopes of rare elements like ~7Li, ~(11)B, ~(138)La, ~(180)Ta and others are predominantly produced by the neutrino interactions with several abundant nuclei. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here first study how to know the suitable average neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the neutrino oscillation parameters, θ_(13) and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process ~(11)B and ~7Li encapsulated in the grains. Combining the recent experimental constraints on θ_(13), we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.