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Related papers: The Galactic positron flux and dark matter substru…

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We are constructing a model which aims to reproduce observational data of many kinds related to cosmic-ray origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, gamma-rays, and synchrotron radiation.…

Astrophysics · Physics 2007-05-23 A. W. Strong , I. V. Moskalenko

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

Observations of annihilation radiation in the Galaxy are briefly reviewed. We summarize astrophysical mechanisms leading to positron production, and recent estimates for production rates from nova and supernova nucleosynthesis in the…

Astrophysics · Physics 2007-05-23 C. D. Dermer , R. J. Murphy

The positron excess in cosmic rays has stimulated a lot of interests in the last decade. The dark matter origin of the extra positrons has attracted great attention. However, the $\gamma$-ray search set very stringent constraints on the…

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

Many models of dark matter contain more than one new particle beyond those in the Standard Model. Often heavier particles decay into the lightest dark matter particle as the Universe evolves. Here we explore the possibilities that arise if…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Lotfi Boubekeur , Scott Dodelson , Oscar Vives

The leaky box model is now ruled out by measurements of a cosmic ray gradient throughout the galactic disk. It needs to be replaced by a more refined treatment which takes into account the diffusion of cosmic rays in the magnetic fields of…

Astrophysics · Physics 2009-10-28 P. Chardonnet , G. Mignola , P. Salati , R. Taillet

We calculate the extragalactic diffuse emission originating from the up-scattering of cosmic microwave photons by energetic electrons and positrons produced in particle dark matter annihilation events at all redshifts and in all halos. We…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-22 Stefano Profumo , Tesla E. Jeltema

Annihilation of Dark Matter usually produces together with gamma rays comparable amounts of electrons and positrons. The e+e- gyrating in the galactic magnetic field then produce secondary synchrotron radiation which thus provides an…

Astrophysics · Physics 2009-08-19 Enrico Borriello , Alessandro Cuoco , Gennaro Miele

If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any…

Astrophysics of Galaxies · Physics 2009-09-28 Le Zhang , Javier Redondo , Guenter Sigl

The EGRET excess of diffuse Galactic gamma rays shows all the features expected from dark matter annihilation (DMA): a spectral shape given by the fragmentation of mono-energetic quarks, which is the same in all sky directions and an…

Astrophysics · Physics 2008-01-09 Iris Gebauer

We study the annihilating dark matter contribution to the extra-galactic diffuse gamma-ray background spectrum, motivated by the recent observations of cosmic-ray positron/electron anomalies. The observed diffuse gamma-ray flux provides…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Masahiro Kawasaki , Kazunori Kohri , Kazunori Nakayama

In this work, we revisit the all-sky Galactic diffuse $\gamma$-ray emission taking into account the new measurements of cosmic ray electron/positron spectrum by PAMELA, ATIC and Fermi, which show excesses of cosmic electrons/positrons…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Juan Zhang , Qiang Yuan , Xiao-Jun Bi

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

Motivated by the anomalous positron flux recently reported by the PAMELA collaboration, we study the cosmic-ray positron produced by the pair annihilation and the decay of superparticle dark matter. We calculate the cosmic-ray positron flux…

High Energy Physics - Phenomenology · Physics 2015-05-13 Koji Ishiwata , Shigeki Matsumoto , Takeo Moroi

A new calculation of the Galactic diffuse gamma-ray spectrum from the decay of secondary particles produced by interactions of cosmic-ray protons with interstellar matter is presented. The calculation utilizes the modern Monte Carlo event…

Astrophysics · Physics 2009-10-28 Masaki Mori

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

The public GALPROP code gives a fully numerical solution for the spectrum of cosmic rays propagating through a linear Galactic wind directed outwards from the Galactic plane in the framework of a cylindrical diffusion model. Alternatively,…

High Energy Astrophysical Phenomena · Physics 2021-06-30 Kwei-Chou Yang

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

Two different model-independent mapping techniques have been applied to OSSE, SMM, TGRS and balloon data and reveal a feature in the 0.511 MeV electron-positron annihilation radiation pattern of our galaxy centered roughly at l=-2 deg. and…

Astrophysics · Physics 2009-10-30 C. D. Dermer , J. G. Skibo

The bulge of our Galaxy is illuminated by the 0.511 MeV gamma-ray line flux from annihilations of nonrelativistic positrons. The emission is strongly concentrated at the Galactic Center, in contrast to gamma-ray maps tracing nucleosynthesis…

Astrophysics · Physics 2008-11-26 Hasan Yuksel