Cross section measurements of proton capture reactions on Mo isotopes relevant to the astrophysical p process

Abstract

Cross section measurements of (p, γ) reactions on the Mo isotopes have been performed at beam energies from 2 to 6.2 MeV that are relevant to the p-process. Partial cross sections and isomeric ratios were also determined for the 92 Mo case. Astrophysical S factors as well as reaction rates were derived from the experimental cross sections. Statistical model calculations were performed using the latest version (1.9) of the statistical model code TALYS and were compared with the new data. An overall good agreement between theory and experiment was found. In addition, the effect of different combinations of the nuclear input parameters entering the stellar reaction-rate calculations was investigated. It was found that, for certain combinations of optical-model potentials, nuclear level densities and γ-ray strength functions, the nuclear uncertainties propagated through the Hauser-Feshbach calculations are less than a factor of 2 which is well below the average discrepancies of the calculated p-nuclei abundances and the observations.