APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Motohiko Kusakabe (Beihang University)
Title: Yields and Routes of p-process Nuclei in Cosmic Rays and Supernovae
Date (JST): Thu, Dec 07, 2017, 13:30 - 14:30
Place: Seminar Room A
Abstract: Stable nuclei heavier than the Fe-peak nuclei in the solar system are classified into the s-nuclei, r-nuclei, and p-nuclei. The s- and the r-nuclei are produced via slow and rapid neutron-capture processes, respectively. The p-nuclei are located in the proton-rich region from the beta-stability line in the nuclear chart. They are produced via the p-process, i.e., photodisintegration and proton-capture reactions on s- and r-nuclei, which are seed nuclei for production of p-nuclei.

We study production of p-nuclei in cosmic ray nucleosynthesis in interstellar medium and in Type Ia supernovae. We show results of yields and routes of p-nuclei by solving a cosmic ray transport utilizing latest observational cosmic ray compositions and an empirical spallation cross section formula. The rare p-nuclide 180Ta as well as 50V is produced via the cosmic ray nucleosynthesis in significant amounts in terms of a contribution to the solar system abundance, and main production routes are identified. The p-process in Type Ia supernovae is investigated taking into account the initial stellar metallicity. We show a sensitivity of yields of p-nuclei to the metallicity, and conclude that p-isotopes of Mo and Ru are not produced significantly for the adopted Type Ia supernova model.