Nuclear weak interactions, supernova nucleosynthesis and neutrino oscillation

International Symposium on Exotic Nuclear Structure From Nucleons 2012

Kajino, Toshitaka^1,2

National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan^1

Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan^2

关键词: Core collapse supernovae;    Flavor oscillations;    Galactic chemical evolutions;    Light-mass nuclei;    Murchison meteorite;    Neutrino oscillations;    Neutrino spectrum;    Weak interactions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/445/1/012024/pdf
DOI  :  10.1088/1742-6596/445/1/012024

来源: IOP

【 摘 要 】

We study the nuclear weak response in light-to-heavy mass nuclei and calculate neutrino-nucleus cross sections. We apply these cross sections to the explosive nucleosynthesis in core-collapse supernovae and find that several isotopes of rare elements7Li,11B,138La,180Ta and several others are predominantly produced by the neutrino-process nucleosynthesis. We discuss how to determine the suitable neutrino spectra of three different flavors and their anti-particles 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. Light-mass nuclei like7Li and11B, which are produced in outer He-layer, are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect, while heavy-mass nuclei like138La,180Ta and r-process elements, which are produced in the inner O-Ne-Mg layer or the atmosphere of proto-neutron star, are likely to be free from the MSW effect. Using such a different nature of the neutrino-process nucleosynthesis, we study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the unknown neutrino oscillation parameters, θ13and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process11B and7Li encapsulated in the grains. Combining the recent experimental constraints on θ13, 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.