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Related papers: The PAMELA Positron Excess from Annihilations into…

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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

This review concentrates on the results obtained, over the last ten years, on the astrophysics of high-energy cosmic ray electrons and positrons. The anomalies, observed in the data of recent experiments (possible bump in the electron…

High Energy Astrophysical Phenomena · Physics 2013-03-26 A. D. Panov

The AMS-02 collaboration has just released its first result of the cosmic positron fraction $e^+/(e^-+e^+)$ with high precision up to $\sim 350$ GeV. The AMS-02 result shows the same trend with the previous PAMELA result, which requires…

High Energy Astrophysical Phenomena · Physics 2014-07-15 Qiang Yuan , Xiao-Jun Bi , Guo-Ming Chen , Yi-Qing Guo , Su-Jie Lin , Xinmin Zhang

The Positron Annihilation into Dark Matter Experiment at the Laboratori Nazionali di Frascati has reported an excess of $e^+e^-$ final-state events from positron annihilation on fixed-target atomic electrons. While the global significance…

High Energy Physics - Phenomenology · Physics 2026-04-15 Fernando Arias-Aragón , Giovanni Grilli di Cortona , Enrico Nardi , Claudio Toni

The possibility that the Galactic dark matter is composed of neutralinos that are just above half the $Z^o$ mass is examined, in the context of the Galactic positron excess. In particular, we check if the anomalous bump in the cosmic ray…

Astrophysics · Physics 2007-05-23 Irit Maor

The AMS-02 collaboration has recently presented measurements of excellent quality of the cosmic electron and positron fluxes as well as the positron fraction. We use the measurements of the positron flux to derive, for the first time,…

High Energy Physics - Phenomenology · Physics 2014-04-02 Alejandro Ibarra , Anna S. Lamperstorfer , Joseph Silk

The muon collider represents one of the most promising solutions for a future machine exploring the high energy frontier, but several challenges due to the 2.2 $\mu$sec muon lifetime at rest have to be carefully considered. The LEMMA…

Recently data from PAMELA, ATIC, FERMI-LAT and HESS show that there are $e^{\pm}$ excesses in the cosmic ray energy spectrum. PAMELA observed excesses only in $e^+$, but not in anti-proton spectrum. ATIC, FERMI-LAT and HESS observed…

High Energy Physics - Phenomenology · Physics 2010-11-15 Xiao-Gang He

The apparent gamma-ray excess in the Galactic center region and inner Galaxy has attracted considerable interest, notably because both its spectrum and radial distribution are consistent with an interpretation in terms of annihilating dark…

High Energy Astrophysical Phenomena · Physics 2014-12-03 Torsten Bringmann , Martin Vollmann , Christoph Weniger

Recently, there are two hints arising from physics beyond the standard model. One is a possible energy loss mechanism due to emission of very weakly interacting light particles from white dwarf stars, with a coupling strength ~…

High Energy Physics - Phenomenology · Physics 2010-01-15 Kyu Jung Bae , Ji-Haeng Huh , Jihn E. Kim , Bumseok Kyae , Raoul D. Viollier

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

Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and ATIC experiments may indicate the existence of annihilating dark matter with large annihilation cross section. We show that the dark matter annihilation in the…

High Energy Physics - Phenomenology · Physics 2010-04-21 Junji Hisano , Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi , Kazunori Nakayama

We estimate the amount of antiprotons and positrons in cosmic rays due to neutralino annihilations in the galactic halo assuming that dark matter tends to cluster and that these clusters are not disturbed by tidal forces. We find that,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Chen Jacoby , Shmuel Nussinov

The large intensity of greater than 10 GeV positrons which apparently come from sources outside the Earth-Sun system observed recently by many spacecraft (PAMELA, FERMI, AMS2) is still a mystery with broad implications. In our attempts to…

Space Physics · Physics 2015-12-23 W. R. Webber

Several recent studies have considered modifications to the standard weakly-interacting massive particle (WIMP) scenario in which the cross section (times relative velocity v) for pair annihilation is enhanced by a factor 1/v. Since…

Astrophysics · Physics 2010-04-21 Marc Kamionkowski , Stefano Profumo

The particle origin of dark matter (DM) is still one of the main puzzles in modern physics. One of the most promising search strategy to detect DM at laboratories is through the indirect search of cosmic particles that are produced from DM…

High Energy Astrophysical Phenomena · Physics 2023-05-04 Haoxiang Zhan

We study a two component dark matter candidate inspired by the Minimal Walking Technicolor model. Dark matter consists of a dominant SIMP-like dark atom component made of bound states between primordial helium nuclei and a doubly charged…

High Energy Astrophysical Phenomena · Physics 2015-09-02 K. Belotsky , M. Khlopov , C. Kouvaris , M. Laletin

Recently the HEAT balloon experiment has confirmed an excess of high-energy positrons in cosmic rays. They could come from annihilation of dark matter in the galactic halo. We discuss expectations for the positron signal in cosmic rays from…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. L. Kane , Lian-Tao Wang , James D. Wells

Simple models of weakly interacting massive particles (WIMPs) predict dark matter annihilations into pairs of electroweak gauge bosons, Higgses or tops, which through their subsequent cascade decays produce a spectrum of gamma rays.…

High Energy Physics - Phenomenology · Physics 2015-05-20 Prateek Agrawal , Brian Batell , Patrick J. Fox , Roni Harnik

PAMELA and ATIC recently reported excesses in e+ e- cosmic rays. Since the interpretation in terms of DM annihilations was found to be not easily compatible with constraints from photon observations, we consider the DM decay hypothesis and…

High Energy Physics - Phenomenology · Physics 2009-05-26 Enrico Nardi , Francesco Sannino , Alessandro Strumia