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

Speaker: Kazunori Kohri (KEK)
Title: Can we explain AMS-02 antiproton and positron excesses simultaneously by nearby supernovae without pulsars nor dark matter?
Date (JST): Wed, Jul 01, 2015, 13:30 - 14:30
Place: Seminar Room A
Abstract: We explain the excess of the antiproton fraction recently reported by the AMS-02 experiment by considering collisions between cosmic-ray protons accelerated by a local supernova remnant (SNR) and the surrounding dense cloud. The same "pp collisions" provide the right branching ratio to fit the observed positron excess simultaneously without a fine tuning. The supernova happened in relatively lower metalicity than the major cosmic-ray sources. The cutoff energy of electrons marks the supernova age of ~10^{5} years, while the antiproton excess may extend to higher energy. Both antiproton and positron fluxes are completely consistent with our predictions in Fujita, Kohri, Yamazaki and Ioka (2009).