EPS-HEP 2017

Antiproton Flux and Antiproton-to-Proton Flux Ratio in Primary Cosmic Rays Measured with AMS on the Space Station

Not scheduled

15m

Salone Adriatico (Palazzo del Casinò)

Board: AP-2

Poster Presentation Astroparticle Physics Poster session

Speaker

Andreas Bachlechner (Rheinisch-Westfaelische Tech. Hoch. (DE))

Description

Precision measurements by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV are presented based on $3.49\times {10}^5$ antiproton events and $2.42\times {10}^9$ proton events. At ~20 GV the antiproton-to-proton flux ratio reaches a maximum. Unexpectedly, above 60 GV the antiproton spectral index is consistent with the proton spectral index and the antiproton-to-proton flux ratio shows no rigidity dependence in the rigidity range from ~60 to ~500 GV. This unexpected observation requires new explanation of the origin of cosmic ray antiprotons.