Limits on dark matter from AMS-02 antiproton and positron fraction data

作者：Lu, Bo-Qiang^*; Zong, Hong-Shi

来源：PHYSICAL REVIEW D, 2016, 93(10): 103517.

DOI：10.1103/PhysRevD.93.103517

• COSMIC-RAY ACCELERATION
• SUPERBUBBLE ORIGIN
• SOLAR MODULATION
• TIME-DELAY
• EXCESS
• ENERGIES
• NUCLEOSYNTHESIS
• PROPAGATION
• SECONDARY
• SPECTRUM

Herein we derive limits on dark matter annihilation cross section and lifetime using measurements of the AMS-02 antiproton ratio and positron fraction data. In deriving the limits, we consider the scenario of secondary particles accelerated in supernova remnants (SNRs), which has been argued to be able to reasonably account for the AMS-02 high-energy positron/antiproton fraction/ratio data. We parametrize the contribution of secondary particles accelerated in SNRs and then fit the observational data within the conventional cosmic ray propagation model by adopting the GALPROP code. We use the likelihood ratio test to determine the 95% confidence level upper limits of possible dark matter (DM) contribution to the antiproton/positron fractions measured by AMS-02. Under the assumption taken in this work, we find that our limits are stronger than that set by the Fermi-LAT gamma ray Pass 8 data observation on the dwarf spheroidal satellite galaxies. We show that the solar modulation (cosmic ray propagation) parameters can play a non-negligible role in modifying the constraints on dark matter annihilation cross section and lifetime for m(chi) < 100 GeV (m(chi) > 100 GeV), where m(chi) is the rest mass of dark matter particles. We also find that constrains on DM parameters from AMS-02 data would become more stringent when the solar modulation is weak. Using these results, we also put limits on the effective field theory of dark matter.

• 出版日期2016-5-18
• 单位南京大学; 中国科学院紫金山天文台