Measurement of key resonances for the 24Al( p,γ )25Si reaction rate using in-beam γ -ray spectroscopy

Abstract
Energy levels and branching ratios for the rp-process nucleus 25Si were determined from the reactions 9Be(26Si,25Si)X and 9Be(25Al,25Si)X using in-beam γ-ray spectroscopy with both high-efficiency and high-resolution detector arrays. Proton-unbound states at 3695(14) and 3802(11) keV were identified and assigned tentative spins and parities based on comparison to theory and the mirror nucleus. The 24Al(p,γ)25Si reaction rate was calculated using the experimental states and states from charge-dependent USDA and USDB shell-model calculations with downward shifts of the 1s1/2 proton orbital to account for the observed Thomas-Ehrman shift, leading to a factor of 10–100 increase in rate for the temperature region of 0.22 GK as compared to a previous calculation. These shifts may be applicable to neighboring nuclei, impacting the proton capture rates in this region of the chart.
Description
CITATION: Longfellow, B., et al. 2018. Measurement of key resonances for the 24Al( p,γ )25Si reaction rate using in-beam γ -ray spectroscopy. Physical Review C, 97(5):054307, doi:10.1103/PhysRevC.97.054307.
The original publication is available at https://journals.aps.org/prc
Keywords
Spin (Physics), Spectroscopy, Resonance (Physics), Nuclei, Thomas-Ehrman shifts, Nuclear Physics -- Research
Citation
Longfellow, B., et al. 2018. Measurement of key resonances for the 24Al( p,γ )25Si reaction rate using in-beam γ -ray spectroscopy. Physical Review C, 97(5):054307, doi:10.1103/PhysRevC.97.054307