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Related papers: The 'PAMELA anomaly' indicates a nearby cosmic ray…

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The positron fraction observed by PAMELA and other experiments up to ~ 100 GeV is analyzed in terms of models of cosmic-ray propagation. It is shown that generically we expect the positron fraction to reach ~ 0.6 at energies of several TeV,…

High Energy Astrophysical Phenomena · Physics 2010-09-08 B. Burch , R. Cowsik

Antiprotons are regarded as a powerful probe for Dark Matter (DM) indirect detection and indeed current data from \PAMELA\ have been shown to lead to stringent constraints. However, in order to exploit their constraining/discovery power…

High Energy Astrophysical Phenomena · Physics 2015-10-28 Mathieu Boudaud

Recent data from ATIC, CREAM and PAMELA indicate that the cosmic ray energy spectra of protons and nuclei exhibit a remarkable hardening at energies above 100 GeV per nucleon. We propose that the hardening is an interstellar propagation…

High Energy Astrophysical Phenomena · Physics 2012-05-29 N. Tomassetti

The flux of electron and positron cosmic rays measured by the space-based experiments PAMELA, AMS-02, CALET, DAMPE and Fermi-LAT shows an unexpected behaviour at high energies, in comparison with expectations from standard astrophysical…

High Energy Physics - Phenomenology · Physics 2020-11-19 Johannes Buchner , Edson Carquin , Marco A. Díaz , Germán A. Gómez-Vargas , Boris Panes , Nicolás Viaux

The excesses in the electron and positron spectra observed by many experiments, such as PAMELA and AMS-02, have sparked significant theoretical investigation. It is not easy to distinguish the two primary hypotheses dark matter…

High Energy Astrophysical Phenomena · Physics 2024-11-07 Xing-Jian Lv , Xiao-Jun Bi , Kun Fang , Peng-Fei Yin , Meng-Jie Zhao

Particle acceleration in the dynamically evolving environment of Supernova Remnants is discussed in the framework of a genuinely time-dependent nonlinear theory, assuming spherical symmetry. As a consequence the dependence of injection on…

Astrophysics · Physics 2007-05-23 H. J. Voelk

We compare the expected abundance of cosmic-ray electrons and positrons from pulsars and magnetars. We assume that the distribution of infant pulsars and magnetars follows that of high-mass stars in the Milky Way and that the production…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Jeremy S. Heyl , Ramandeep Gill , Lars Hernquist

The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the…

High Energy Astrophysical Phenomena · Physics 2017-06-19 Ilias Cholis , Dan Hooper , Tim Linden

Recent measurements of cosmic ray electrons and positrons by PAMELA, ATIC, Fermi and HESS have revealed interesting excesses and features in the GeV-TeV range. Many possible explanations have been suggested, invoking one or more nearby…

High Energy Astrophysical Phenomena · Physics 2010-02-01 Pierre Brun , Gianfranco Bertone , Marco Cirelli , Emmanuel Moulin , Jean-Francois Glicenstein , Fabio Iocco , Lidia Pieri

We show that the PAMELA anomaly in the positron fraction as well as the ATIC/PPB-BETS excesses in the e^- + e^+ flux are simultaneously explained in our scenario that a hidden U(1)H gauge boson constitutes dark matter of the Universe and…

Astrophysics · Physics 2009-09-28 Chuan-Ren Chen , Mihoko M. Nojiri , Fuminobu Takahashi , T. T. Yanagida

Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. Several signatures, ranging from the positron excess, as observed…

Astrophysics · Physics 2009-11-13 W. de Boer

Recent measurements of the Geminga and B0656+14 pulsars by the gamma-ray telescope HAWC (along with earlier measurements by Milagro) indicate that these objects generate significant fluxes of very high-energy electrons. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2017-11-22 Dan Hooper , Ilias Cholis , Tim Linden , Ke Fang

The cosmic ray data of PAMELA/ATIC may be explained by dark matter decay with a decay rate $\tau_{DM}^{-1}\sim 10^{-26}{sec}^{-1} \sim 10^{-45}{eV}$, an energy scale which could not be understood within the framework of the standard model…

High Energy Physics - Phenomenology · Physics 2009-09-11 Hiroki Fukuoka , Jisuke Kubo , Daijiro Suematsu

At energies above a few TeV, no measurements of the cosmic-ray electron spectrum exist yet. By considering the similarity of air showers induced by electrons and gamma rays as seen by ground-based arrays, we use published limits on…

High Energy Astrophysical Phenomena · Physics 2009-12-03 Matthew D. Kistler , Hasan Yuksel

We study diffuse gamma-ray emission at intermediate Galactic latitudes measured by the Fermi Large Area Telescope with the aim of searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal,…

High Energy Astrophysical Phenomena · Physics 2013-04-10 G. Zaharijas , J. Conrad , A. Cuoco , Z. Yang

Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section. Depending on the assumptions made regarding cosmic ray…

High Energy Astrophysical Phenomena · Physics 2015-03-19 Dan Hooper , Tim Linden , Philipp Mertsch

Since the PAMELA results on the "anomalously" high positron fraction and the lack of antiproton excess in our Galaxy, there has been a tremendous number of studies advocating new types of dark matter, with larger couplings to electrons than…

High Energy Physics - Phenomenology · Physics 2014-11-20 Celine Boehm , Timur Delahaye , Pierre Salati , Florian Staub , Ritesh K. Singh

The observations of the total electronic component and the positron fraction in cosmic rays by the FERMI, HESS, ATIC, and PAMELA instruments are studied with analytical propagation models, both for a set of discrete sources and for a…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-15 R. Cowsik , B. Burch

We propose a novel mechanism to explain the positron excesses, which are observed by satellite-based telescopes including PAMELA and AMS-02, in dark matter (DM) scenarios. The novelty behind the proposal is that it makes direct use of DM…

High Energy Physics - Phenomenology · Physics 2018-05-09 Doojin Kim , Jong-Chul Park , Seodong Shin