Systematic study of the uncertainties in fitting the cosmic positron data by AMS-02

Abstract

The operation of AMS-02 opens a new era for the study of cosmic ray physics with unprecedentedly precise data which are comparable with the laboratory measurements. The high precision data allow a quantitative study on the cosmic ray physics and give strict constraints on the nature of cosmic ray sources. However, the intrinsic errors from the theoretical models to interpret the data become dominant over the errors in the data. In the present work we try to give a systematic study on the uncertainties of the models to explain the AMS-02 positron fraction data, which shows the cosmic ray $e^{+}{e}^{-}$ excesses together with the PAMELA and Fermi-LAT measurements. The excesses can be attributed to contributions from the extra $e^{+}{e}^{-}$ sources, such as pulsars or the dark matter annihilation. The possible systematic uncertainties of the theoretical models considered include the cosmic ray propagation, the treatment of the low energy data, the solar modulation, the $pp$ interaction models, the nuclei injection spectrum and so on. We find that in general a spectral hardening of the primary electron injection spectrum above $\sim 50-100$ GeV is favored by the data. Furthermore, the present model uncertainties may lead to a factor of $\sim 2$ enlargement in the determination of the parameter regions of the extra source, such as the dark matter mass, annihilation rate and so on.

20 pages (JCAP style), 6 figures and 6 tables; accepted for publication in JCAP

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Cited by in corpus (4)

• AMS-02 Positron Excess and Indirect Detection of Three-body Decaying Dark Matter
• Interpreting the galactic center gamma-ray excess in the NMSSM
• Forecasting of the time-dependent fluxes of antiprotons in the AMS-02 era
• Probing solar modulation of AMS-02 time-dependent D, ${}^3$He and ${}^4$He fluxes with modified force field approximation