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Related papers: The anomaly in the cosmic-ray positron spectrum

200 papers

Detecting and characterizing the anisotropy pattern of the arrival directions of the highest energy cosmic rays are crucial steps towards the identification of their sources. We discuss a possible distortion of the cosmic ray flux induced…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Sihem Kalli , Martin Lemoine , Kumiko Kotera

The spectral shape of cosmic ray positrons and antiprotons has been accurately measured in the broad kinetic energy range 1-350 GeV. In the higher part of this range (E > 30 GeV) the e+ and pbar are both well described by power laws with…

High Energy Astrophysical Phenomena · Physics 2017-03-15 Paolo Lipari

The fine tuning of parameters required to reproduce our present day Universe suggests that our Universe may simply be a region within an eternally inflating super-region. Many other regions beyond our observable Universe would exist with…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 R. Chary

Electron and positron fluxes in cosmic rays are currently measured with unprecedented precision by AMS-02 up to TeV energies, and represent unique probes for the local properties of our Galaxy. The interpretation of their spectra is at…

High Energy Astrophysical Phenomena · Physics 2022-09-13 Silvia Manconi

A precision measurement by AMS-02 of the positron fraction in primary cosmic rays is presented on this proceeding. Over the last two decades, there has been a strong interest in the cosmic ray positron fraction which exhibit an excess of…

High Energy Astrophysical Phenomena · Physics 2017-01-02 Sami Caroff

Recently the AMS-02 collaboration has published the measurement of the cosmic antiproton to proton ratio $\bar{p}/p$ and the $\bar{p}$ flux with a high precision up to $\sim 450\,\mathrm{GeV}$. In this work, we perform a systematic analysis…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Su-Jie Lin , Xiao-Jun Bi , Jie Feng , Peng-Fei Yin , Zhao-Huan Yu

Cosmic ray antiprotons provide a powerful tool to probe dark matter annihilations in our galaxy. The sensitivity of this important channel is, however, diluted by sizable uncertainties in the secondary antiproton background. In this work,…

High Energy Physics - Phenomenology · Physics 2017-03-08 Martin Wolfgang Winkler

The recently observed data by AMS-02 clearly confirms that the positron flux rises with energy and shows a peak near a few hundred GeV. This rising positron flux cannot be explained by interactions of cosmic rays with interstellar hydrogen…

High Energy Astrophysical Phenomena · Physics 2020-12-23 Agnibha De Sarkar , Sayan Biswas , Nayantara Gupta

We show that the recent AMS02 positron fraction measurement is consistent with a secondary origin for positrons, and does not require additional primary sources such as pulsars or dark matter. The measured positron fraction at high energy…

High Energy Astrophysical Phenomena · Physics 2013-11-27 Kfir Blum , Boaz Katz , Eli Waxman

The cosmic ray energy spectra of protons and helium nuclei, which are the most abundant components of cosmic radiation, exhibit a remarkable hardening at energies above one hundred GeV/nucleon. Recent data from AMS-02 confirms this feature…

High Energy Astrophysical Phenomena · Physics 2017-02-08 Behrouz Khiali , Sadakazu Haino , Jie Feng

Growing evidence reveals universal hardening on various cosmic ray spectra, e.g. proton, positron, as well as antiproton fraction. Such universality may indicate they have a common origin. In this paper, we argue that these widespread…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Wei Liu , Xiao-Jun Bi , Su-Jie Lin , Bing-Bing Wang , Peng-Fei Yin

The latest AMS-02 data on cosmic ray electrons show a break in the energy spectrum around 40 GeV, with a change in the slope of about 0.1. We perform a combined fit to the newest AMS-02 positron and electron flux data above 10 GeV using a…

High Energy Astrophysical Phenomena · Physics 2021-10-29 Mattia Di Mauro , Fiorenza Donato , Silvia Manconi

We have developed 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. Our…

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

In the last decade, a number of experiments dealt with the problem of measuring the arrival direction distribution of cosmic rays, looking for information on the propagation mechanisms and the identification of their sources. Any deviation…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Roberto Iuppa , Giuseppe Di Sciascio

Galactic diffuse continuum gamma-ray emission is intricately related to cosmic-ray physics and radio astronomy. We describe recent results from an approach which endeavours to take advantage of this. Information from cosmic-ray composition…

Astrophysics · Physics 2010-12-13 A. W. Strong , I. V. Moskalenko , O. Reimer

There is tentative evidence for a mismatch between the rest frames of matter and the cosmic microwave background, the "quasar dipole anomaly". We consider such a dipole in tilted anisotropic models, for a range of scenarios and sources:…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-04 Alicia Martín , Constantinos Skordis , Deaglan J. Bartlett , Harry Desmond , Pedro G. Ferreira , Tariq Yasin

A previous work (Monteser\'in et al. 2008) estimated the CMB variance from the three-year WMAP data, finding a lower value than expected from Gaussian simulations using the WMAP best-fit cosmological model. We repeat the analysis on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Cruz , P. Vielva , E. Martínez-González , R. B. Barreiro

Pulsars are considered to be the leading explanation for the excess in cosmic-ray positrons detected by PAMELA and AMS-02. A notable feature of standard pulsar models is the sharp spectral cutoff produced by the increasingly efficient…

High Energy Astrophysical Phenomena · Physics 2023-05-24 Isabelle John , Tim Linden

Based on general considerations rather than model-dependent fits to specific scenarios, we argue that an increase with energy of the positron fraction in cosmic rays, suggested by several experiments at E>~7 GeV, most likely requires a…

High Energy Physics - Phenomenology · Physics 2010-04-21 Pasquale Dario Serpico