Interpretation of the cosmic ray positron and antiproton fluxes Article Swipe
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· 2017
· Open Access
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· DOI: https://doi.org/10.1103/physrevd.95.063009
· OA: W2493914704
The spectral shape of cosmic ray positrons and antiprotons has been\naccurately measured in the broad kinetic energy range 1-350 GeV. In the higher\npart of this range (E > 30 GeV) the e+ and pbar are both well described by\npower laws with spectral indices gamma[e+] = 2.77 +-0.02 and gamma[pbar] = 2.78\n+- 0.04 that are approximately equal to each other and to the spectral index of\nprotons.\n In the same energy range the positron/antiproton flux ratio has the\napproximately constant value 2.04+-0.04, that is consistent with being equal to\nthe ratio e_/pbar calculated for the conventional mechanism of production,\nwhere the antiparticles are created as secondaries in the inelastic\ninteractions of primary cosmic rays with interstellar gas.\n The positron/antiproton ratio at lower energy is significantly higher\n(reaching the approximate value e+/pbar = 100 for E around 1 GeV), but in the\nentire energy range 1-350 GeV, the flux ratio is consistent with being equal to\nratio of the production rates in the conventional mechanism, as the production\nof low energy antiprotons is kinematically suppressed in collisions with a\ntarget at rest.\n These results strongly suggest that cosmic ray positrons and antiprotons have\na common origin as secondaries in hadronic interactions. This conclusion has\nbroad implications for the astrophysics of cosmic rays in the Galaxy.\n
