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Related papers: Cosmic Ray Positrons from Annihilations into a New…

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We examine whether the cosmic ray positron excess observed by PAMELA can be explained by neutralino annihilation in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The main dark matter annihilation products are the lightest…

High Energy Physics - Phenomenology · Physics 2009-09-04 Yang Bai , Marcela Carena , Joseph Lykken

The recently observed excess in gamma-ray signal near the Galactic center suggests that dark matter particles may annihilate into charged fermions that produce gamma-ray to be observed. In this paper, we consider a leptonic dark matter,…

High Energy Physics - Phenomenology · Physics 2016-09-29 Jongkuk Kim , Jong-Chul Park , Seong Chan Park

Recently, new data on antiprotons and positrons from PAMELA, e- + e+ spectra from ATIC, FERMI and HESS up to TeV energies all indicate deviations from expectations, which has caused an interesting mix of new explanations, ranging from…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Wim de Boer

We calculate the flux of cosmic positrons from the dark matter annihilation in the littlest Higgs model with T-parity. The dark matter annihilates mainly into weak gauge bosons in the halo, and high energy positrons are produced through…

High Energy Physics - Phenomenology · Physics 2008-11-26 Masaki Asano , Shigeki Matsumoto , Nobuchika Okada , Yasuhiro Okada

Due to their higher concentrations and small internal velocities, Milky Way subhalos can be at least as important as the smooth halo in accounting for the GeV positron excess via dark matter annihilation. After showing how this can be…

High Energy Astrophysical Phenomena · Physics 2010-08-13 Matthew D. Kistler , Jennifer M. Siegal-Gaskins

The decay of dark matter is predicted by many theoretical models and can produce observable contributions to the cosmic-ray fluxes. I shortly discuss the interpretation of the positron and electron excess as observed by PAMELA and Fermi LAT…

High Energy Physics - Phenomenology · Physics 2009-10-30 Christoph Weniger

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

It has been long discussed that cosmic rays may contain signals of dark matter. In the last couple of years an anomaly of cosmic-ray positrons has drawn a lot of attentions, and recently an excess in cosmic-ray anti-proton has been reported…

High Energy Physics - Phenomenology · Physics 2016-06-29 Shin'ichiro Ando , Koji Ishiwata

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

We study cosmic-rays in decaying dark matter scenario, assuming that the dark matter is the lightest superparticle and it decays through a R-parity violating operator. We calculate the fluxes of cosmic-rays from the decay of the dark matter…

High Energy Physics - Phenomenology · Physics 2010-12-14 Koji Ishiwata , Shigeki Matsumoto , Takeo Moroi

We propose that the leptonic cosmic ray signals seen by PAMELA and ATIC result from the annihilation or decay of dark matter particles via states of a leptonic Higgs doublet to $\tau$ leptons, linking cosmic ray signals of dark matter to…

High Energy Physics - Phenomenology · Physics 2009-05-29 Hock-Seng Goh , Lawrence J. Hall , Piyush Kumar

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

We reconsider Sommerfeld-enhanced annihilation of dark matter (DM) into leptons to explain PAMELA and Fermi electron and positron observations, in light of possible new effects from substructure. There is strong tension between getting a…

High Energy Physics - Phenomenology · Physics 2010-12-23 Aaron C Vincent , Wei Xue , James M Cline

In supersymmetric unified theories the dark matter particle can decay, just like the proton, through grand unified interactions with a lifetime of order of 10^{26} sec. Its decay products can be detected by several experiments -- including…

High Energy Physics - Phenomenology · Physics 2009-09-24 Asimina Arvanitaki , Savas Dimopoulos , Sergei Dubovsky , Peter W. Graham , Roni Harnik , Surjeet Rajendran

The AMS experiment onboard the International Space Station has recently provided cosmic ray electron and positron data with unprecedented precision in the range from 0.5 to 350 GeV. The observed rise in the positron fraction at energies…

High Energy Astrophysical Phenomena · Physics 2013-10-29 Lars Bergstrom , Torsten Bringmann , Ilias Cholis , Dan Hooper , Christoph Weniger

Particles with TeV mass and strong self-interactions generically have the right annihilation cross section to explain an observed excess of cosmic electrons and positrons if the end-product of the annihilation is charged leptons. We present…

High Energy Physics - Phenomenology · Physics 2010-08-12 Yi Cai , David E. Kaplan , Markus A. Luty

We discuss the cosmic ray spectra in annihilating/decaying Nambu-Goldstone dark matter models. The recent observed positron/electron excesses at PAMELA and Fermi experiments are well fitted by the dark matter with a mass of 3TeV for the…

High Energy Physics - Phenomenology · Physics 2009-12-04 Masahiro Ibe , Hitoshi Murayama , Satoshi Shirai , Tsutomu T. Yanagida

The Galactic positrons, as observed by their annihilation gamma-ray line at 0.511 MeV, are difficult to account for with astrophysical sources. It has been proposed that they are produced instead by dark matter annihilation or decay in the…

Astrophysics · Physics 2009-07-09 John F. Beacom , Nicole F. Bell , Gianfranco Bertone

We consider a simple class of models in which the dark matter, X, is coupled to a new gauge boson, phi, with a relatively low mass (m_phi \sim 100 MeV-3 GeV). Neither the dark matter nor the new gauge boson have tree-level couplings to the…

High Energy Physics - Phenomenology · Physics 2013-05-30 Dan Hooper , Neal Weiner , Wei Xue

Motivated by the PAMELA anomaly in the fluxes of cosmic-ray positron and electron, we study the cosmic gamma-ray induced by the inverse Compton (IC) scattering process in unstable dark matter scenario assuming that the anomaly is due to the…

High Energy Physics - Phenomenology · Physics 2015-05-14 Koji Ishiwata , Shigeki Matsumoto , Takeo Moroi