Gamma width ofO*14(5.17 MeV) and the stellarN13(p)14O reaction rate

Abstract
We have determined the γ-ray branching ratio Γγ/Γtot for the first excited state in O14 (Ex=5.17 MeV) to be (3.1±1.7)×104, corresponding to a γ width of 12±7 eV. This value was determined by measuring the ratio of the N14(p,n)14 O0 to N14(p,n)14 O1 cross sections via neutron time of flight, and the ratio of N14(p,n)14 O0 to N14(p,n)14 O1)14 O0 cross sections at the same center-of-mass energy by bombarding a hydrogen target with a N14 beam and kinematically distinguishing the O014 recoils from the two reaction channels. The present value for Γγ is consistent with other measurements at the 2-σ level; a weighted mean of all measurements is used to calculate the stellar N13(p)14O reaction rate, and thereby determine the temperatures and densities at which the stellar carbon-nitrogen-oxygen (CNO) cycle is converted to the hot CNO cycle.