Evidence for nucleosynthesis in supernova $\gamma$-process: Universal   scaling on p-nuclei
  With analyzing the solar system abundance, we have found two universal scaling laws concerning the p- and s-nuclei. They indicate that the gamma-process in supernova (SN) explosions is the most promising origin of the p-nuclei that has been discussed with many possible nuclear reactions and sites for about fifty years. In addition the scalings provide new concepts: an universality of the gamma-process and a new nuclear cosmochronometer. We have carried out gamma-process nucleosynthesis calculations for typical core-collapse SN explosion models and the results satisfy the observed scalings. 
T.Hayakawa, N.Iwamoto, T.Shizuma, T.Kajino, H.Umeda, and K. Nomoto