The synthesis of the light Mo and Ru isotopes: how now, no need for an exotic solution ?

The most detailed calculations of the p-process call for its development in the O/Ne layers of Type II supernovae. In spite of their overall success in reproducing the solar system content of p-nuclides, they suggest a significant underproduc- tion of the light Mo and Ru isotopes. On grounds of a model for the explosion of a 25 M star with solar metallicity, we demon- strate that this failure might just be related to the uncertainties left in the rate of the 22 Ne( ;n) 25 Mg neutron producing re- action. The latter indeed have a direct impact on the distribution of the s-process seeds for the p-process.