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Title: Isospin mixing reveals 30P(p, γ)31S resonance influencing nova nucleosynthesis

Here, the thermonuclear 30P(p, γ)31S reaction rate is critical for modeling the final elemental and isotopic abundances of ONe nova nucleosynthesis, which affect the calibration of proposed nova thermometers and the identification of presolar nova grains, respectively. Unfortunately, the rate of this reaction is essentially unconstrained experimentally, because the strengths of key 31S proton capture resonance states are not known, largely due to uncertainties in their spins and parities. Using the β decay of 31Cl, we have observed the β-delayed γ decay of a 31S state at Ex = 6390.2(7) keV, with a 30P(p, γ)31S resonance energy of Er = 259.3(8) keV, in the middle of the 30P(p, γ)31S Gamow window for peak nova temperatures. This state exhibits isospin mixing with the nearby isobaric analog state at Ex = 6279.0(6) keV, giving it an unambiguous spin and parity of 3/2+ and making it an important l = 0 resonance for proton capture on 30P.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [1] ;  [1] ;  [1] ;  [3] ;  [5] ;  [1] ;  [2] ;  [6] ;  [1] ;  [1] ;  [7] more »;  [1] ;  [8] ;  [3] ;  [1] « less
  1. Michigan State Univ., East Lansing, MI (United States)
  2. Univ. of Notre Dame, Notre Dame, IN (United States)
  3. McMaster Univ., Hamilton, ON (Canada)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  5. Michigan State Univ., East Lansing, MI (United States); Univ. of Notre Dame, Notre Dame, IN (United States)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  7. Michigan State Univ., East Lansing, MI (United States); Univ. of Southern Indiana, Evansville, IN (United States)
  8. Univ. of Tennessee, Knoxville, TN (United States)
Publication Date:
OSTI Identifier:
1261528
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 116; Journal Issue: 10; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS