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Related papers: Cosmic Rays below Z=30 in a diffusion model: new c…

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More than 100 years after the discovery of cosmic rays and various experimental efforts, the origin of ultra-high energy cosmic rays (E > 100 PeV) remains unclear. The understanding of production and propagation effects of these highest…

High Energy Astrophysical Phenomena · Physics 2014-09-23 Daniel Kuempel

Recently AMS-02 collaboration publish their measurements of light cosmic-ray nuclei, including lithium, beryllium, boron, carbon and oxygen. All of them reveal a prominent excess above $\sim$ 200 GV, coinciding with proton and helium.…

High Energy Astrophysical Phenomena · Physics 2019-01-09 Wei Liu , Yu-hua Yao , Yi-Qing Guo

Sub-GeV dark matter candidates are of increasing interest, because long-favored candidates such as GeV-scale WIMPs have not been detected. For low-mass dark matter, model-independent constraints are weak or nonexistent. We show that for…

High Energy Physics - Phenomenology · Physics 2019-07-09 Christopher V. Cappiello , Kenny C. Y. Ng , John F. Beacom

Isotropic diffusion models for Galactic cosmic ray transport put tight constraints on the maximum convection velocity in the halo. For a half halo height of 4 kpc the maximum convection speed is limited to 40 km/s in the halo, since…

Astrophysics of Galaxies · Physics 2009-10-13 Iris Gebauer , Wim de Boer

It is well established that phenomenological two-zone diffusion models of the galactic halo can very well reproduce cosmic-ray nuclear data and the observed antiproton flux. Here, we consider lepton propagation in such models and compute…

Astrophysics of Galaxies · Physics 2015-05-28 Torsten Bringmann , Fiorenza Donato , Roberto A. Lineros

A fundamental problem of cosmic ray (CR) physics is the determination of the average properties of Galactic CRs outside the Solar system. Starting from COS-B data in the 1980's, gamma-ray observations of molecular clouds in the Gould Belt…

High Energy Astrophysical Phenomena · Physics 2015-06-05 M. Kachelriess , S. Ostapchenko

Recent observations show that the cosmic ray nuclei spectra start to harden above 100 GeV, in contradiction with the conventional steady-state cosmic ray model. We had suggested that this anomaly is due to the propagation effect of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Wei Liu , Pierre Salati , Xuelei Chen

Diffusion coefficients are usually used to describe the propagation of Cosmic Rays through the Universe. Whereas such transport parameters can be obtained from experiments in the Solar System, it is difficult to determine diffusion…

Astrophysics of Galaxies · Physics 2015-06-12 Kaitlynn Buffie , Volker Heesen , Andreas Shalchi

Recent measurements of cosmic ray proton and helium spectra show a hardening above a few hundreds of GeV. This excess is hard to understand in the framework of the conventional models of Galactic cosmic ray production and propagation. We…

High Energy Astrophysical Phenomena · Physics 2013-10-01 Guilhem Bernard , Timur Delahaye , Yong-Yeon Keum , Wei Liu , Pierre Salati , Richard Taillet

The recent discovery of diffuse, VHE gamma radiation from the Galactic center ridge by the H.E.S.S. telescope allow for the first time the direct determination of parameters of galactic cosmic ray propagation models. In this paper we show…

Astrophysics · Physics 2008-11-26 I. Büsching , O. C. de Jager , J. Snyman

Old models of the scattering of composite systems based on the Glauber model of multiple diffraction are applied to hadron-nucleus scattering. We obtain an excellent fit with only two free parameters to the highest energy hadron-nucleus…

High Energy Physics - Phenomenology · Physics 2009-10-28 James S. Ball , Anthony Pantziris

The standard model of cosmic ray propagation has been very successful in explaining all kinds of the Galactic cosmic ray spectra. However, high precision measurement recently revealed the appreciable discrepancy between data and model…

High Energy Astrophysical Phenomena · Physics 2017-02-22 Y. Q. Guo , H. B. Hu , Z. Tian

In this work we develop a new propagation model for the Galactic cosmic rays based on the GALPROP code, including contributions from dark matter annihilation. The model predicts compatible Galactic diffuse $\gamma$ ray spectra with EGRET…

Astrophysics · Physics 2008-11-26 Xiao-Jun Bi , Juan Zhang , Qiang Yuan

The antiparticle energy spectra of Galactic cosmic rays (CRs) have several exciting features such as the unexpected positron excess at $E\sim$10-200\,GeV and the remarkably hard antiproton flux at $E\sim$\,60--450\,GeV recently measured by…

High Energy Astrophysical Phenomena · Physics 2018-07-31 Jie Feng , Nicola Tomassetti , Alberto Oliva

Recent precise measurements of cosmic ray spectral revealed an anomalous hardening at ~200 GV for nuclei from PAMELA, CREAM, ATIC, AMS02 experiments and at tens of GeV for primary electron derived from AMS02 experiment. Particularly, the…

High Energy Astrophysical Phenomena · Physics 2018-04-11 Yi-Qing Guo , Zhen Tian , Chao Jin

Astrophysical neutrinos are expected to be produced in the interactions of ultra-high energy cosmic-rays with surrounding photons. The fluxes of the astrophysical neutrinos are highly dependent on the characteristics of the cosmic-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Shigeru Yoshida , Aya Ishihara

Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal and dynamical evolution. The purpose of this work is to explore the possibility that a low-energy component of…

Solar and Stellar Astrophysics · Physics 2015-05-13 Marco Padovani , Daniele Galli , Alfred E. Glassgold

Analytical calculations of extra-galactic cosmic ray spectra above ~10^17 eV are often performed assuming continuous source distributions, giving rise to spectra that depend little on the propagation mode, be it rectilinear or diffusive. We…

Astrophysics · Physics 2008-11-26 Guenter Sigl

The study of Galactic diffuse $\gamma$ radiation combined with the knowledge of the distribution of the molecular hydrogen in the Galaxy offers a unique tool to probe the cosmic ray flux in the Galaxy. A methodology to study the level of…

Astrophysics · Physics 2009-11-13 S. Casanova , S. Gabici , F. A. Aharonian , K. Torii , Y. Fukui , T. Onishi , H. Yamamoto , A. Kawamura
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