Fermi-LAT kills dark matter interpretations of AMS-02 data. Or not?

Journal Article · Sun Jan 01 04:00:00 EST 2017 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2017/01/021· OSTI ID:22680098

Belotsky, Konstantin; Budaev, Ruslan; Kirillov, Alexander; Laletin, Maxim ^[1]

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1. Department of Elementary Particle Physics, National Research Nuclear University MEPhI, 115409 Kashirskoe shosse 31, Moscow (Russian Federation)

A number of papers attempt to explain the positron anomaly in cosmic rays, observed by PAMELA and AMS-02, in terms of dark matter (DM) decays or annihilations. However, the recent progress in cosmic gamma-ray studies challenges these attempts. Indeed, as we show, any rational DM model explaining the positron anomaly abundantly produces final state radiation and Inverse Compton gamma rays, which inevitably leads to a contradiction with Fermi-LAT isotropic diffuse gamma-ray background measurements. Furthermore, the Fermi-LAT observation of Milky Way dwarf satellites, supposed to be rich in DM, revealed no significant signal in gamma rays. We propose a generic approach in which the major contribution to cosmic rays comes from the dark matter disc and prove that the tension between the DM origin of the positron anomaly and the cosmic gamma-ray observations can be relieved. We consider both a simple model, in which DM decay/annihilate into charged leptons, and a model-independent minimal case of particle production, and we estimate the optimal thickness of DM disk. Possible mechanisms of formation and its properties are briefly discussed.

• OSTI ID: 22680098
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2017; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
COMPTON EFFECT
COSMIC GAMMA SOURCES
COSMIC PHOTONS
COSMIC POSITRONS
DECAY
GAMMA RADIATION
MILKY WAY
NONLUMINOUS MATTER
PARTICLE PRODUCTION
POSITRONS
SATELLITES
THICKNESS