論文

査読有り
2019年9月23日

Experimental constraint on stellar electron-capture rates from the Sr 88 (t, He 3 +γ) Rb 88 reaction at 115 MeV/u

Physical Review C
  • J. C. Zamora
  • ,
  • R. G.T. Zegers
  • ,
  • Sam M. Austin
  • ,
  • D. Bazin
  • ,
  • B. A. Brown
  • ,
  • P. C. Bender
  • ,
  • H. L. Crawford
  • ,
  • J. Engel
  • ,
  • A. Falduto
  • ,
  • A. Gade
  • ,
  • P. Gastis
  • ,
  • B. Gao
  • ,
  • T. Ginter
  • ,
  • C. J. Guess
  • ,
  • S. Lipschutz
  • ,
  • B. Longfellow
  • ,
  • A. O. Macchiavelli
  • ,
  • K. Miki
  • ,
  • E. Ney
  • ,
  • S. Noji
  • ,
  • J. Pereira
  • ,
  • J. Schmitt
  • ,
  • C. Sullivan
  • ,
  • R. Titus
  • ,
  • D. Weisshaar

100
3
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.1103/PhysRevC.100.032801

The Gamow-Teller strength distribution from Sr88 was extracted from a (t,He3+γ) experiment at 115MeV/u to constrain estimates for the electron-capture rates on nuclei around N=50, between and including Ni78 and Sr88, which are important for the late evolution of core-collapse supernovae. The observed Gamow-Teller strength below an excitation energy of 8 MeV was consistent with zero and below 10 MeV amounted to 0.1±0.05. Except for a very-weak transition that could come from the 2.231-MeV 1+ state, no γ lines that could be associated with the decay of known 1+ states were identified. The derived electron-capture rate from the measured strength distribution is more than an order of magnitude smaller than rates based on the single-state approximation presently used in astrophysical simulations for most nuclei near N=50. Rates based on shell-model and quasiparticle random-phase approximation calculations that account for Pauli-blocking and core-polarization effects provide better estimates than the single-state approximation, although a relatively strong transition to the first 1+ state in Rb88 is not observed in the data. Pauli-unblocking effects due to high stellar temperatures could partially counter the low electron-capture rates. The new data serve as a zero-temperature benchmark for constraining models used to estimate such effects.

リンク情報
DOI
https://doi.org/10.1103/PhysRevC.100.032801
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85072984236&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85072984236&origin=inward
ID情報
  • DOI : 10.1103/PhysRevC.100.032801
  • ISSN : 2469-9985
  • eISSN : 2469-9993
  • SCOPUS ID : 85072984236

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