Physics Letters B (Jun 2021)

First experimental determination of the radiative-decay probability of the 31− state in 12C for estimating the triple alpha reaction rate in high temperature environments

  • M. Tsumura,
  • T. Kawabata,
  • Y. Takahashi,
  • S. Adachi,
  • H. Akimune,
  • S. Ashikaga,
  • T. Baba,
  • Y. Fujikawa,
  • H. Fujimura,
  • H. Fujioka,
  • T. Furuno,
  • T. Hashimoto,
  • T. Harada,
  • M. Ichikawa,
  • K. Inaba,
  • Y. Ishii,
  • N. Itagaki,
  • M. Itoh,
  • C. Iwamoto,
  • N. Kobayashi,
  • A. Koshikawa,
  • S. Kubono,
  • Y. Maeda,
  • Y. Matsuda,
  • S. Matsumoto,
  • K. Miki,
  • T. Morimoto,
  • M. Murata,
  • T. Nanamura,
  • I. Ou,
  • S. Sakaguchi,
  • A. Sakaue,
  • M. Sferrazza,
  • K.N. Suzuki,
  • T. Takeda,
  • A. Tamii,
  • K. Watanabe,
  • Y.N. Watanabe,
  • H.P. Yoshida,
  • J. Zenihiro

Journal volume & issue
Vol. 817
p. 136283

Abstract

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The triple alpha reaction is one of the most important reactions in the nuclear astrophysics. However, its reaction rate in high temperature environments at T9> 2 was still uncertain. One of the major origins of the uncertainty was that the radiative-decay probability of the 31− state in 12C was unknown. In the present work, we have determined the radiative-decay probability of the 31− state to be 1.3−1.1+1.2×10−6 by measuring the 1H(12C,12Cp) reaction for the first time, and derived the triple alpha reaction rate in high temperature environments from the measured radiative-decay probability. The present result suggests that the 31− state noticeably enhances the triple alpha reaction rate although the contribution from the 31− state had been assumed to be small.

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