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

作者：Al Abdullah T^*; Carstoiu F; Chen X; Clark H L; Fu C; Gagliardi C A; Lui Y W; Mukhamedzhanov A; Tabacaru G; Tokimoto Y; Trache L; Tribble R E

来源：Physical Review C, 2010, 81(3): 035802.

DOI：10.1103/PhysRevC.81.035802

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

• 出版日期2010-3