The AMS-02 collaboration has released preliminary data on the antiproton fraction in cosmic rays. The surprisingly hard antiproton spectrum at high rigidity has triggered speculations about a possible primary antiproton component originating from dark matter annihilations. In this note, we employ newly available AMS-02 boron to carbon data to update the secondary antiproton flux within the standard two-zone diffusion model. The new background permits a considerably better fit to the measured antiproton fraction compared to previous estimates. This is mainly a consequence of the smaller slope of the diffusion coefficient favored by the new AMS-02 boron to carbon data.
@article{arxiv.1506.04145,
title = {AMS-02 Antiprotons Reloaded},
author = {Rolf Kappl and Annika Reinert and Martin Wolfgang Winkler},
journal= {arXiv preprint arXiv:1506.04145},
year = {2015}
}