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Title: β -delayed γ decay of P 26 : Possible evidence of a proton halo

In this study, measurements of β decay provide important nuclear structure information that can be used to probe isospin asymmetries and inform nuclear astrophysics studies. Purpose: To measure the β-delayed γ decay of 26P and compare the results with previous experimental results and shell-model calculations. A 26P fast beam produced using nuclear fragmentation was implanted into a planar germanium detector. Its β-delayed γ-ray emission was measured with an array of 16 high-purity germanium detectors. Positrons emitted in the decay were detected in coincidence to reduce the background. As a result, the absolute intensities of 26P β-delayed γ-rays were determined. A total of six new β-decay branches and 15 new γ-ray lines have been observed for the first time in 26P β-decay. A complete β-decay scheme was built for the allowed transitions to bound excited states of 26Si. ft values and Gamow-Teller strengths were also determined for these transitions and compared with shell model calculations and the mirror β-decay of 26Na, revealing significant mirror asymmetries. A very good agreement with theoretical predictions based on the USDB shell model is observed. The significant mirror asymmetry observed for the transition to the first excited state (δ = 51(10)%) may be evidence for amore » proton halo in 26P.« less
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  1. Michigan State Univ., East Lansing, MI (United States)
  2. Michigan State Univ., East Lansing, MI (United States); Kalamazoo College, Kalamazoo, MI (United States)
  3. McMaster Univ., Hamilton, ON (Canada)
  4. Colorado School of Mines, Golden, CO (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  5. Yale Univ., New Haven, CT (United States)
  6. Michigan State Univ., East Lansing, MI (United States); Univ. of Washington, Seattle, WA (United States)
  7. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  8. Michigan State Univ., East Lansing, MI (United States); Univ. of Southern Indiana, Evansville, IN (United States)
  9. Michigan State Univ., East Lansing, MI (United States); Univ. of Notre Dame, Notre Dame, IN (United States)
Publication Date:
Grant/Contract Number:
NA0000979; FG02-97ER41020
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 93; Journal Issue: 6; Journal ID: ISSN 2469-9985
American Physical Society (APS)
Research Org:
Univ. of California, Berkeley, CA (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1258306