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Related papers: The PAMELA Positron Excess from Annihilations into…

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We consider the capture of dark matter in the Sun by inelastic scattering against nuclei as in the inelastic dark matter scenario. We show that, assuming a WIMP-nucleon cross-section of \sigma_n = 10^{-40}\cm^2 the resulting capture rate…

High Energy Physics - Phenomenology · Physics 2009-09-28 Shmuel Nussinov , Lian-Tao Wang , Itay Yavin

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

The recently reported result from XENON1T experiment indicates that there is an excess with $3.5\sigma$ significance in the electronic recoil events. Interpreted as new physics, new sources are needed to account for the electronic…

High Energy Physics - Phenomenology · Physics 2021-03-03 P. Ko , Yong Tang

Positron and electron cosmic rays provide a complementary way to study the galactic environment. The actual cosmic rays experiments, for instance PAMELA and HEAT, have presented very exciting results in this field. The observed positron…

Astrophysics · Physics 2009-02-04 Roberto A. Lineros

Fermi-LAT has confirmed the excess in cosmic positron fraction observed by PAMELA, which could be explained by dark matter annihilating or decaying in the center of the galaxy. Most existing models postulate that the dark matter annihilates…

High Energy Physics - Phenomenology · Physics 2015-06-05 Hsin-Chia Cheng , Wei-Chih Huang , Ian Low , Gabe Shaughnessy

We compute in detail the rate at which energy injected by dark matter annihilation heats and ionizes the photon-baryon plasma at z ~ 1000, and provide accurate fitting functions over the relevant redshift range for a broad array of…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 Tracy R. Slatyer , Nikhil Padmanabhan , Douglas P. Finkbeiner

Two new observations have strengthened the case for the supersymmetric nature of the Cold Dark Matter component in our universe: First, it was shown that new data on the nuclear abundance, B/C - and 10Be/9Be ratios constrain the diffusion…

High Energy Physics - Phenomenology · Physics 2016-09-06 W. de Boer , M. Herold , C. Sander , V. Zhukov

In this paper, we study the flux of electrons and positrons injected by pulsars and by annihilating or decaying dark matter in the context of recent ATIC, PAMELA, Fermi, and HESS data. We review the flux from a single pulsar and derive the…

High Energy Astrophysical Phenomena · Physics 2009-09-17 Dmitry Malyshev , Ilias Cholis , Joseph Gelfand

A solution to the PAMELA positron excess with Higgsino dark matter within extended supergravity grand unified (SUGRA) models is proposed. The models are compliant with the photon constraints recently set by Fermi-LAT and produce positron as…

High Energy Physics - Phenomenology · Physics 2011-02-03 Ning Chen , Daniel Feldman , Zuowei Liu , Pran Nath , Gregory Peim

A number of signals involving charged cosmic rays and high-energy photons have been interpreted as being due to annihilating dark matter. This article provides an overview of the experimental evidence and discusses in particular detections…

Astrophysics · Physics 2007-05-23 U. Schwanke

A stable Dirac fermion with four-fermion interactions to leptons suppressed by a scale Lambda ~ 1 TeV is shown to provide a viable candidate for dark matter. The thermal relic abundance matches cosmology, while nuclear recoil direct…

High Energy Physics - Phenomenology · Physics 2010-04-28 Roni Harnik , Graham D. Kribs

Very recently, PAMELA Collaboration has formally reported two sets of data on positron and antiproton flux measurements done at very high energies and with unprecedented accuracy. The reports reveal a puzzle of great topical interest and…

High Energy Astrophysical Phenomena · Physics 2009-07-17 Goutam Sau , S. K. Biswas , S. Bhattacharyya

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

Motivated by a recent detection of 511 keV photons from the center of our Galaxy, we calculate the spectrum of the soft gamma-ray background of the redshifted 511 keV photons from cosmological halos. Annihilation of dark matter particles…

Astrophysics · Physics 2009-11-10 Kyungjin Ahn , Eiichiro Komatsu

For explaining the AMS-02 cosmic positron excess, which was recently reported, we consider a scenario of thermally produced and decaying dark matter (DM) into the standard model (SM) leptons with an extremely small decay rate, \Gamma_{DM}…

High Energy Physics - Phenomenology · Physics 2014-05-02 Ki-Young Choi , Bumseok Kyae , Chang Sub Shin

We study in this paper the scenario where the dark matter is constituted by Majorana particles which couple to a light Standard Model fermion and an extra scalar via a Yukawa coupling. In this scenario, the annihilation rate into the light…

High Energy Physics - Phenomenology · Physics 2015-06-03 Mathias Garny , Alejandro Ibarra , Stefan Vogl

There is convincing observational evidence for an increasing cosmic-ray positron-to-electron ratio at energies larger than $\sim 10$~GeV, at odds with expectations from secondary positron production. The most recent AMS-02 data exhibit an…

High Energy Physics - Phenomenology · Physics 2019-03-21 Stefano Profumo , Farinaldo Queiroz , Clarissa Siqueira

We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current…

High Energy Physics - Phenomenology · Physics 2015-06-24 Chuan-Hung Chen , Cheng-Wei Chiang , Takaaki Nomura

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

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