Department of Physics, Panjab University, Chandigarh, India

TPSC seminar

Date and time: 19 May 2014 (Monday), 2:30 pm
Venue: Seminar Hall

Title: No more anomaly in the TeV-scale cosmic-ray proton and helium spectra (an explanation of PAMELA-CREAM anomaly)

Speaker: Prof. Yong-Yeon Keum, Institute of Basic Science / Department of Physics, Seoul National University, Seoul, Republic of Korea

Abstract: Recent measurements of cosmic ray proton and helium spectra show a hardening above a few hundreds of GeV. This excess is hard to understand in the framework of the conventional models of Galactic cosmic ray production and propagation. We propose here to explain this anomaly by the presence of local sources (myriad model). Cosmic ray propagation is described as a diffusion process taking place inside a two-zone magnetic halo. We calculate the proton and helium fluxes at the Earth between 50 GeV and 100 TeV. Improving over a similar analysis, we consistently derive these fluxes by taking into account both local and remote sources for which a unique injection rate is assumed. We find cosmic ray propagation parameters compatible with B/C measurements and for which the proton and helium spectra remarkably agree with the PAMELA and CREAM measurements over four decades in energy.