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Related papers: $e^\pm$ Excesses in the Cosmic Ray Spectrum and Po…

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The unexpected energy spectrum of the positron/electron ratio is interpreted astrophysically, with a possible exception of the 100-300 GeV range. The data indicate that this ratio, after a decline between $0.5-8$ GeV, rises steadily with a…

High Energy Astrophysical Phenomena · Physics 2016-10-11 M. A. Malkov , P. H. Diamond , R. Z. Sagdeev

The large intensity of greater than 10 GeV positrons which apparently come from sources outside the Earth-Sun system observed recently by many spacecraft (PAMELA, FERMI, AMS2) is still a mystery with broad implications. In our attempts to…

Space Physics · Physics 2015-12-23 W. R. Webber

Recent preliminary results from the PAMELA experiment indicate the presence of an excess of cosmic ray positrons above 10 GeV. In this letter, we consider possibility that this signal is the result of dark matter annihilations taking place…

High Energy Physics - Phenomenology · Physics 2009-12-30 Ilias Cholis , Lisa Goodenough , Dan Hooper , Melanie Simet , Neal Weiner

Recent results from the PAMELA satellite indicate the presence of a large flux of positrons (relative to electrons) in the cosmic ray spectrum between approximately 10 and 100 GeV. As annihilating dark matter particles in many models are…

Astrophysics · Physics 2010-04-15 Dan Hooper , Pasquale Blasi , Pasquale Dario Serpico

Fermi measurements of the high-latitude gamma-ray background strongly constrain a decaying-dark-matter origin for the 1--100 GeV Galactic positron anomaly measured with PAMELA. Inverse-Compton scattering of the microwave background by the…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Martin Pohl , David Eichler

A recent analysis of cosmic-ray data from a space borne experiment by the AMS collaboration supports the observation of an excess in the cosmic-ray positron spectrum by previous balloon experiments. The combination of the various…

Astrophysics · Physics 2007-10-15 C. H. Chung , H. Gast , J. Olzem , S. Schael

The overabundance of high-energy cosmic positrons, observed by PAMELA and AMS-02, can be considered as the consequence of dark matter decays or annihilations. We show that recent FERMI/LAT measurements of the isotropic diffuse gamma-ray…

High Energy Astrophysical Phenomena · Physics 2016-07-11 Maxim Laletin

We investigate the observed spectrum of cosmic-ray electrons and positrons from astrophysical sources, especially pulsars, and the physical processes for making the spectrum spiky or smooth via continuous and multiple electron/positron…

High Energy Astrophysical Phenomena · Physics 2015-04-23 Norita Kawanaka , Kunihito Ioka , Mihoko M. Nojiri

A strong excess in a form of a wide peak in the energy range of 300-800 GeV was discovered in the first measurements of the electron spectrum in the energy range from 20 GeV to 3 TeV by the balloon-borne experiment ATIC (J. Chang et al.…

In light of recent observations of an anomalous excess of high-energy positrons and electrons by the PAMELA and Fermi LAT experiments, we investigate exotic cosmic-ray signatures in scenarios with unstable dark matter that decays with an…

High Energy Physics - Phenomenology · Physics 2015-05-14 David Tran

Precision measurements of the positron flux in cosmic ray have revealed an unexplained bump in the spectrum around $E\simeq 300\,\mathrm{GeV}$, not clearly attributable to known astrophysical processes. We propose annihilation of dark…

High Energy Physics - Phenomenology · Physics 2020-06-11 Anirban Das , Basudeb Dasgupta , Anupam Ray

Predefined spatial templates to describe the background of $\gamma$-ray emission from astrophysical processes, like cosmic ray interactions, are used in previous searches for the $\gamma$-ray signatures of annihilating galactic dark matter.…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Xiaoyuan Huang , Torsten Enßlin , Marco Selig

Recent observations of cosmic ray protons in the energy range $10^2$--$10^5$~GeV have revealed that the spectrum cannot be described by a simple power law. A hardening of the spectrum around an energy of order few hundred~GeV, first…

High Energy Astrophysical Phenomena · Physics 2020-04-01 Paolo Lipari , Silvia Vernetto

The AMS-02 collaboration has recently released data on the positron fraction $e^+/(e^-+e^+)$ up to energies of about 350 GeV. If one insists on interpreting the observed excess as a dark matter signal, then we find it is best described by a…

High Energy Physics - Phenomenology · Physics 2013-05-06 Andrea De Simone , Antonio Riotto , Wei Xue

Recent observations of lepton cosmic rays, coming from the PAMELA and FERMI experiments, have pushed our understanding of the interstellar medium and cosmic rays sources to unprecedented levels. The imprint of dark matter on lepton cosmic…

High Energy Astrophysical Phenomena · Physics 2011-01-27 Roberto A. Lineros

Data of Pierre Auger Observatory show a proton-dominated chemical composition of ultrahigh-energy cosmic rays spectrum at (1 - 3) EeV and a steadily heavier composition with energy increasing. In order to explain this feature we assume that…

High Energy Astrophysical Phenomena · Physics 2012-09-25 R. Aloisio , V. Berezinsky , A. Gazizov

Cosmic-ray and gamma-ray observations have yielded several notable excesses that often lend themselves to explanation by various dark matter annihilation/decay models. In particular, the AMS-02 anti-proton and positron excesses have…

High Energy Astrophysical Phenomena · Physics 2019-09-04 Geoff Beck

Recently the ATIC and PAMELA collaborations released their results which show the abundant e^\pm excess in cosmic rays well above the background, but not for the \bar{p}. Their data if interpreted as the dark matter particles' annihilation…

High Energy Physics - Phenomenology · Physics 2009-06-02 Xiao-Jun Bi , Pei-Hong Gu , Tianjun Li , Xinmin Zhang

We reveal that the energy spectra of electrons-positrons in primary cosmic rays measured at atmosphere top have double structures: an excess component $\Phi^s_{e^+}(E)=\Phi^s_{e^-}(E)$ around $400 GeV$, which origins from a strong…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Wei Zhu , Pen Liu , Jianhong Ruan , Lei Feng , Fan Wang