Astrophysical 22Mg(p, γ)23Al reaction rates from asymptotic normalization coefficient of 23Ne→22Ne+n * * Supported by the National Key Research and Development Program of China (2016YFA0400502), the National Natural Science Foundation of China (11975316, 11490561, 11535004, 11775013), the Continuous Basic Scientific Research Project (WDJC-2019-13) and the 973 Program (2013CB834406)

Abstract

The radionuclide 22Na generates the emission of a characteristic 1.275 MeV -ray. This is a potential astronomical observable, whose occurrence is suspected in classical novae. The reaction is relevant to the nucleosynthesis of 22Na in Ne-rich novae. In this study, employing the adiabatic distorted wave approximation and continuum discretized coupled channel methods, the squared neutron asymptotic normalization coefficients (ANCs) for the virtual decay of + n were extracted, and determined as fm−1 and fm−1 for the ground state and the first excited state from the experimental angular distributions of populating the ground state and the first excited state of , respectively. Then, the squared proton ANC of was obtained as fm−1 according to the charge symmetry of the strong interaction. The astrophysical S-factors and reaction rates for the direct capture contribution in were also presented. Furthermore, the proton width of the first excited state of was derived to be eV from the neutron ANC of its mirror state in and used to compute the contribution from the first resonance of . This result demonstrates that the direct capture dominates the reaction at most temperatures of astrophysical relevance for .