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Related papers: The PAMELA Positron Excess from Annihilations into…

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Recent PAMELA data show that positron fraction has an excess above several GeV while anti-proton one is not. Moreover ATIC data indicates that electron/positron flux have a bump from 300 GeV to 800 GeV. Both annihilating dark matter (DM)…

Astrophysics · Physics 2009-03-26 Jia Liu , Peng-fei Yin , Shou-hua Zhu

We study a fermionic dark matter in a non-supersymmetric extension of the standard model with a family symmetry based on D6xZ2xZ2. In our model, the final state of the dark matter annihilation is determined to be e+ e- by the flavor…

High Energy Physics - Phenomenology · Physics 2014-08-19 Yuji Kajiyama , Hiroshi Okada , Takashi Toma

Multiple lines of evidence indicate an anomalous injection of high-energy e+- in the Galactic halo. The recent $e^+$ fraction spectrum from the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) shows a sharp…

Astrophysics · Physics 2009-12-30 Ilias Cholis , Gregory Dobler , Douglas P. Finkbeiner , Lisa Goodenough , Neal Weiner

Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been…

Astrophysics · Physics 2009-10-06 T. Delahaye , F. Donato , N. Fornengo , J. Lavalle , R. Lineros , P. Salati , R. Taillet , .

The Fermi experiment has measured the cosmic ray electron+positron spectrum and positron fraction [$\Phi_{e^+}/(\Phi_{e^+ + e^-})]$, and PAMELA has measured the positron fraction with better precision. While the majority of cosmic ray…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-04 Arjun Sharma

In the framework of the Inert Doublet Model, a very simple extension of the Standard Model, we study the production and propagation of antimatter in cosmic rays coming from annihilation of a scalar dark matter particle. We consider three…

High Energy Physics - Phenomenology · Physics 2009-05-06 Emmanuel Nezri , Michel H. G. Tytgat , Gilles Vertongen

The recent report by the PAMELA team of the observed rise in the cosmic-ray positron fraction above a few GeV and the report of an excess of cosmic-ray electrons around a few hundred GeV by the ATIC collaboration has resulted in a flurry of…

High Energy Astrophysical Phenomena · Physics 2009-05-05 Michael Schubnell

It is shown that a Weakly Interacting Massive dark matter Particle (WIMP) interpretation for the positron excess observed in a variety of experiments, HEAT, PAMELA, and AMS-02, is highly constrained by the Fermi/LAT observations of dwarf…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-06 Alejandro Lopez , Christopher Savage , Douglas Spolyar , Douglas Q. Adams

The recent high energy electron and positron flux observed by the DAMPE experiment indicates possible excess events near 1.4 TeV. Such an excess may be evidence of dark matter annihilations or decays in a dark matter subhalo that is located…

High Energy Physics - Phenomenology · Physics 2018-08-22 Xuewen Liu , Zuowei Liu

The spectrum and morphology of gamma-rays from the Galactic Center and the spectrum of synchrotron emission observed from the Milky Way's radio filaments have each been interpreted as possible signals of $\sim$7-10 GeV dark matter particles…

High Energy Astrophysical Phenomena · Physics 2013-05-30 Dan Hooper , Wei Xue

We construct a thermal dark matter model with annihilation mediated by a resonance to explain the positron excess observed by PAMELA, Fermi-LAT and AMS-02, while satisfying constraints from cosmic microwave background (CMB) measurements.…

High Energy Physics - Phenomenology · Physics 2018-06-13 Yang Bai , Joshua Berger , Sida Lu

The PAMELA and Fermi measurements of the cosmic-ray electron and positron spectra have generated much interest over the past two years, because they are consistent with a significant component of the electron and positron fluxes between 20…

High Energy Physics - Phenomenology · Physics 2011-08-05 Spencer Chang , Lisa Goodenough

The radiative seesaw model with an inert doublet has been shown to be attractive from a viewpoint of both neutrino masses and cold dark matter. However, if we apply this model to the explanation of the positron excess in the cosmic ray…

High Energy Physics - Phenomenology · Physics 2014-11-20 Daijiro Suematsu , Takashi Toma , Tetsuro Yoshida

If dark matter (DM) annihilation accounts for the tantalizing excess of cosmic ray electron/positrons, as reported by the PAMELA, ATIC, HESS and FERMI observatories, then the implied annihilation cross section must be relatively large. This…

High Energy Physics - Phenomenology · Physics 2012-03-15 A. A. El-Zant , S. Khalil , H. Okada

A leading interpretation of the electron/positron excesses seen by PAMELA and ATIC is dark matter annihilation in the galactic halo. Depending on the annihilation channel, the electron/positron signal could be accompanied by a galactic…

High Energy Physics - Phenomenology · Physics 2009-09-29 Jeremy Mardon , Yasunori Nomura , Daniel Stolarski , Jesse Thaler

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

The annihilation of light dark matter was recently advocated as a possible explanation of the large positron injection rate at the Galactic center deduced from observations by the SPI spectrometer aboard INTEGRAL. The modelling of internal…

Astrophysics · Physics 2008-11-26 P. Sizun , M. Casse , S. Schanne

We discuss the recently observed `excesses' in cosmic ray electron and positron fluxes which have been widely interpreted as signals of dark matter. By considering the production and acceleration of secondary electrons and positrons in…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Philipp Mertsch , Subir Sarkar

We take the recent result from the CDMS collaboration as a hint that the dark matter has an elastic scattering cross section with the nucleon in the vicinity of 10^-7 pb. By crossing symmetry such a cross section implies annihilation of…

High Energy Physics - Phenomenology · Physics 2014-11-20 Qing-Hong Cao , Ian Low , Gabe Shaughnessy

We use recently released data on the positron-to-electron ratio in cosmic rays from the AMS-02 experiment to constrain dark matter annihilation in the Milky Way. Due to the yet unexplained positron excess, limits are generally weaker than…

High Energy Physics - Phenomenology · Physics 2013-10-31 Joachim Kopp