Understanding the mirror asymmetry in Gamow-Teller transition rates between ²⁸Al(β^-)^28mSi and ²⁸P(β⁺)^28mSi

2024/02/14 by Xayavong, L., Smirnova, N. A., Lim, Y.
#FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th)

paper · doi:10.48550/arxiv.2402.08914

Abstract

The long-standing discrepancy between shell-model and experimental values of the mirror asymmetry in Gamow-Teller transition rates for ²⁸Al(β^-)^28mSi and ²⁸P(β⁺)^28mSi is partially resolved by integrating the p-orbital contribution into the radial mismatch correction term. This approach offers a potential estimate of the radial mismatch-induced core-orbital contribution based on the French-Macfarlane sum rules, avoiding the need for heavy calculations required by the first-principle shell model. Additionally, the isospin-mixing contribution undergoes considerable improvement through scaling the calculated isospin-mixing correction with the experimental energy separation between the lowest two admixed states, in accordance with the result from the two-level model.

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