\A{31}Cl beta decay and the \A{30}P\pg\A{31}S reaction rate in nova nucleosynthesis

ORAL

Abstract

The \A{30}P\pg\A{31}S reaction rate is critical for modeling the final isotopic abundances of ONe nova nucleosynthesis, identifying the origin of presolar nova grains, and calibrating proposed nova thermometers. Unfortunately, this rate is essentially experimentally unconstrained because the strengths of key \A{31}S proton capture resonances are not known, due to uncertainties in their spins and parities. Using a \A{31}Cl beam produced at the National Superconducting Cyclotron Laboratory, we have populated several \A{31}S states for study via beta decay and devised a new decay scheme which includes updated beta feedings and gamma branchings as well as multiple states previously unobserved in \A{31}Cl beta decay. Results of this study, including the unambiguous identification due to isospin mixing of a new $l = 0$, $J^\pi = 3/2^+$ \A{31}S resonance directly in the middle of the Gamow Window, will be presented, and significance to the evaluation of the \A{30}P\pg\A{31}S reaction rate will be discussed.

*Work supported by U.S. Natl. Sci. Foundation (Grants No. PHY-1102511, PHY-1404442, PHY-1419765, and PHY-1431052); U.S. Dept. of Energy, Natl. Nucl. Security Administration (Award No. DE-NA0000979); Nat. Sci. and Eng. Research Council of Canada

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Authors

  • Michael Bennett

    • Michigan State U. Dept. of Physics and Astronomy, National Superconducting Cyclotron Laboratory, Joint Institute for Nuclear Astrophysics

  • C. Wrede

    • Michigan State U. Dept of Physics and Astronomy, National Superconducting Cyclotron Laboratory
    • MSU/NSCL
    • NSCL/MSU

  • B. A. Brown

    • National Superconducting Cyclotron Laboratory

  • S. N. Liddick

    • National Superconducting Cyclotron Laboratory, Michigan State U. Dept of Chemistry

  • D. Pérez-Loureiro

    • Michigan State U. Dept of Physics and Astronomy, National Superconducting Cyclotron Laboratory