Stellar reaction rate for (22)Mg + p -> (23)Al from the asymptotic normalization coefficient in the mirror nuclear system (22)Ne + n -> (23)Ne

Abstract

The production of (22)Na in ONe novae can be influenced by the (22)Mg(p,gamma)(23)Al reaction. To investigate this reaction rate at stellar energies, we have determined the asymptotic normalization coefficient (ANC) for (22)Mg + p -> (23)Al through measurements of the ANCs in the mirror nuclear system (22)Ne + n -> (23)Ne. The peripheral neutron-transfer reactions (13)C((12)C, (13)C)(12)C and (13)C((22)Ne, (23)Ne)(12)C were studied. The identical entrance and exit channels of the first reaction make it possible to extract independently the ground-state ANC in (13)C. Our experiment gives C(p1/2)(2) ((13)C) = 2.24 +/- 0.11 fm(-1), which agrees with the value obtained from several previous measurements. The weighted average for all the obtained C(p1/2)(2) is 2.31 +/- 0.08 fm(-1). This value is adopted to be used in obtaining the ANCs in 23Ne. The differential cross sections for the reaction (13)C((22)Ne, (23)Ne) (12)C leading to the J(pi) = 5/2(+) and 1/2(+) states in (23)Ne have been measured at 12 MeV/u. Optical model parameters for use in the DWBA calculations were obtained from measurements of the elastic scatterings (22)Ne + (13)C and (22)Ne + (12)C. The extracted ANC for the ground state in (23)Ne, C(d5/2)(2) = 0.86 +/- 0.08 +/- 0.12 fm(-1), is converted to its corresponding value in (23)Al using mirror symmetry to give C(d5/2)(2) ((23)Al) = (4.63 +/- 0.77) x 10(3) fm(-1). The astrophysical S factor S(0) for the (22)Mg(p, gamma) reactionwas determined to be 0.96 +/- 0.11 keVb. The consequences for nuclear astrophysics are discussed.