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Related papers: The PAMELA Positron Excess from Annihilations into…

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We discuss bounds to strong gravity arising from annihilation of electron and positrons and the corresponding enhancement of the cross section for the production of massive particles. Two complementary examples are discussed, the case of…

High Energy Physics - Phenomenology · Physics 2024-07-03 Nathaniel Alden , Roberto Onofrio

(Abridged) The extragalactic background light (EBL) observed at multiple wavelengths is a promising tool to probe the nature of dark matter since it might contain a significant contribution from gamma-rays produced promptly by dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-30 Jesus Zavala , Mark Vogelsberger , Tracy R. Slatyer , Abraham Loeb , Volker Springel

Motivated by specific connections to dark matter signatures, we study the prospects of observing the presence of a relatively light gluino whose mass is in the range ~(500-900) GeV with a wino-like lightest supersymmetric particle with mass…

High Energy Physics - Phenomenology · Physics 2010-04-30 Daniel Feldman , Gordon Kane , Ran Lu , Brent D. Nelson

The flux of high-energy astrophysical $\gamma$ rays is attenuated by the production of electron-positron pairs from scattering off of extragalactic background light (EBL). We use the most up-to-date information on galaxy populations to…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-25 José Luis Bernal , Andrea Caputo , Gabriela Sato-Polito , Jordan Mirocha , Marc Kamionkowski

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

A puzzling excess in gamma-rays at GeV energies has been observed in the center of our galaxy using Fermi-LAT data. Its origin is still unknown, but it is well fitted by Weakly Interacting Massive Particles (WIMPs) annihilations into quarks…

High Energy Physics - Phenomenology · Physics 2017-11-15 Giorgio Arcadi , Farinaldo S. Queiroz , Clarissa Siqueira

Recently the DArk Matter Particle Explorer (DAMPE) has reported an excess in the electron-positron flux of the cosmic rays which is interpreted as a dark matter particle with the mass about $1.5$ TeV. We come up with a leptophilic $Z'$…

High Energy Physics - Phenomenology · Physics 2018-06-13 Karim Ghorbani , Parsa Hossein Ghorbani

The lightest neutralino is a viable dark matter (DM) candidate. In this paper we study indirect detection of the wino-like neutralino DM using positrons and antiprotons from the annihilation in the galactic halo. When the mass is around 2…

High Energy Physics - Phenomenology · Physics 2009-11-11 Junji Hisano , Shigeki Matsumoto , Osamu Saito , Masato Senami

Excesses on positron and electron fluxes measured by ATIC, and the PAMELA and Fermi--LAT telescopes can be explained by dark matter annihilation in our Galaxy. However, this requires large boosts on the dark matter annihilation rate. There…

High Energy Physics - Phenomenology · Physics 2013-05-30 Ivone F. M. Albuquerque , Leandro J. Beraldo e Silva , Carlos Pérez de los Heros

An excess of $\sim$10-20 GeV cosmic-ray antiprotons has been identified in the spectrum reported by the AMS-02 Collaboration. The systematic uncertainties associated with this signal, however, have made it difficult to interpret these…

High Energy Astrophysical Phenomena · Physics 2019-08-20 Ilias Cholis , Tim Linden , Dan Hooper

The excess of electrons/positrons observed by the Pamela and ATIC experiments gives rise to a noticeable amount of synchrotron and Inverse Compton Scattering (ICS) radiation when the e^+e^- interact with the Galactic Magnetic Field, and the…

Astrophysics of Galaxies · Physics 2011-02-11 E. Borriello , A. Cuoco , G. Miele

Recent observations of cosmic ray electrons from several instruments have revealed various degrees of deviation in the measured electron energy distribution from a simple power-law, in a form of an excess around TeV energies. An even more…

Astrophysics of Galaxies · Physics 2015-05-13 Lukasz Stawarz , Vahe Petrosian , Roger D. Blandford

We propose two viable scenarios explaining the recent observations on cosmic positron excess. In both scenarios, the present relic density in the Universe is assumed to be still supported by thermally produced WIMP or LSP (\chi). One of the…

High Energy Physics - Phenomenology · Physics 2011-01-27 Bumseok Kyae

The electron and positron cosmic rays puzzle has triggered a revolution in the field of astroparticle physics. Many hypotheses have been proposed to explain the unexpected rise of the positron fraction, observed by HEAT and PAMELA…

High Energy Astrophysical Phenomena · Physics 2011-01-20 Roberto Alfredo Lineros

Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS, we propose that dark matter is a TeV-scale particle that annihilates into a pseudoscalar "axion." The positron excess and the absence of an anti-proton or gamma ray…

High Energy Physics - Phenomenology · Physics 2010-04-28 Yasunori Nomura , Jesse Thaler

Antimatter cosmic-rays are used to probe new phenomena in physics, including dark matter annihilation. We use the cosmic-ray positron fraction spectrum by the Alpha Magnetic Spectrometer, to search for such an annihilation signal in the…

High Energy Astrophysical Phenomena · Physics 2023-01-18 Iason Krommydas , Ilias Cholis

The $W$-boson mass ($m_{W}=80.4335 \pm 0.0094 \mathrm{GeV}$) measured by the Collider Detector at Fermilab collaboration is greater than the standard model (SM) prediction at a confidence level of $7\sigma$, strongly suggesting the presence…

High Energy Physics - Phenomenology · Physics 2023-02-22 Guan-Wen Yuan , Lei Zu , Lei Feng , Yi-Fu Cai , Yi-Zhong Fan

Using a new instrument, the HEAT collaboration has confirmed the excess of cosmic ray positrons that they first detected in 1994. We explore the possibility that this excess is due to the annihilation of neutralino dark matter in the…

Astrophysics · Physics 2017-08-23 Edward A. Baltz , Joakim Edsjo , Katherine Freese , Paolo Gondolo

Using the latest AMS-02 cosmic ray antiproton flux data, we search for potential dark matter annihilation signal. The background parameters about the propagation, source injection, and solar modulation are not assumed {\it a priori}, but…

High Energy Astrophysical Phenomena · Physics 2017-05-17 Ming-Yang Cui , Qiang Yuan , Yue-Lin Sming Tsai , Yi-Zhong Fan

We explore the dark matter sector in extensions of the Minimal Supersymmetric Standard Model (MSSM) that can provide a good fit to the PAMELA cosmic ray positron excess, while at the same time addressing the little hierarchy problem of the…

High Energy Physics - Phenomenology · Physics 2014-11-20 Francesc Ferrer , Christopher Spitzer