Determination of the astrophysical 12N(p,γ)13O reaction rate from the 2H(12N,13O)n reaction and its astrophysical implications

The evolution of massive stars with very low-metallicities depends critically on the amount of CNO nuclides which they produce. The N-12(p, gamma)O-13 reaction is an important branching point in the rap processes, which are believed to be alternative paths to the slow 3 alpha process for producing CNO seed nuclei and thus could change the fate of massive stars. In the present work, the angular distribution of the H-2(N-12, O-13)n proton transfer reaction at E-c.m. = 8.4 MeV has been measured for the first time. Based on the Johnson-Soper approach, the square of the asymptotic normalization coefficient (ANC) for the virtual decay of O-13(g.s.) -> N-12 + p was extracted to be 3.92 +/- 1.47 fm(-1) from the measured angular distribution and utilized to compute the direct component in the N-12(p, gamma)O-13 reaction. The direct astrophysical S factor at zero energy was then found to be 0.39 +/- 0.15 keV b. By considering the direct capture into the ground state of O-13, the resonant capture via the first excited state of O-13 and their interference, we determined the total astrophysical S factors and rates of the N-12(p, gamma)O-13 reaction. The new rate is two orders of magnitude slower than that from the REACLIB compilation. Our reaction network calculations with the present rate imply that N-12(p, gamma)O-13 will only compete successfully with the beta(+) decay of N-12 at higher (similar to 2 orders of magnitude) densities than initially predicted. DOI: 10.1103/PhysRevC.87.015803