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Related papers: Absolute electron and positron fluxes from PAMELA/…

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Recent PAMELA data show that positron fraction has an excess above several GeV while anti-proton one is not. Moreover ATIC data indicates that electron/positron flux have a bump from 300 GeV to 800 GeV. Both annihilating dark matter (DM)…

Astrophysics · Physics 2009-03-26 Jia Liu , Peng-fei Yin , Shou-hua Zhu

The PAMELA satellite has observed an excess in the positron to electron ratio above theoretical predictions in the range 10 - 100 GeV that increases with energy. We propose that the excess is not due to a change in the local interstellar…

High Energy Astrophysical Phenomena · Physics 2012-11-06 J. P. Roberts

In continuation of their earlier measurements, the PAMELA group reported data on antiproton flux and $\bar{P}/P$ ratios in 2010 at much higher energies. In past we had dealt with these specific aspects of PAMELA data in great detail and…

High Energy Astrophysical Phenomena · Physics 2012-08-06 Goutam Sau , S. Bhattacharyya

Recent results from the AMS-02 data have confirmed that the cosmic ray positron fraction increases with energy between 10 and 200GeV. This quantity should not exceed 50%, and it is hence expected that it will either converge towards 50% or…

High Energy Astrophysical Phenomena · Physics 2014-10-13 Timur Delahaye , Kumiko Kotera , Joseph Silk

In this symposium the Fermi-LAT collaboration released the results of its measurement of the $e^-$ and $e^+$ separate spectra, obtained using the Earth magnetic field. Those results confirm PAMELA finding of an increasing positron fraction…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Dario Grasso , Daniele Gaggero

Recently the PAMELA experiment has released its updated anti-proton flux and anti-proton to proton flux ratio data up to energies of ~200GeV. With no clear excess of cosmic ray anti-protons at high energies, one can extend constraints on…

High Energy Astrophysical Phenomena · Physics 2011-09-28 Ilias Cholis

Fermi-LAT has confirmed the excess in cosmic positron fraction observed by PAMELA, which could be explained by dark matter annihilating or decaying in the center of the galaxy. Most existing models postulate that the dark matter annihilates…

High Energy Physics - Phenomenology · Physics 2015-06-05 Hsin-Chia Cheng , Wei-Chih Huang , Ian Low , Gabe Shaughnessy

The excess of cosmic-ray positrons in the energy range from 10 GeV to few hundred GeV reported by PAMELA and AMS experiments is not consistent with a pure secondary origin and requires the introduction of a source term. The presence of…

Instrumentation and Methods for Astrophysics · Physics 2015-10-07 J. Berdugo , J. Casaus , C. Mana , M. A. Velasco

Recently, tentative evidence for an excess of gamma rays at energies around 130 GeV has been reported from analyses of data from the Fermi Large Area Telescope (LAT). The excess is potentially of great interest, as it could be associated…

High Energy Astrophysical Phenomena · Physics 2012-07-04 Stefano Profumo , Tim Linden

We reveal that the energy spectra of electrons-positrons in primary cosmic rays measured at atmosphere top have double structures: an excess component $\Phi^s_{e^+}(E)=\Phi^s_{e^-}(E)$ around $400 GeV$, which origins from a strong…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Wei Zhu , Pen Liu , Jianhong Ruan , Lei Feng , Fan Wang

We attempt to interpret the cosmic-ray positron excess by injection from the nearby pulsar Geminga, assuming a two-zone diffusion scenario and an injection spectrum with a low energy cutoff. Since the high energy positrons and electrons…

High Energy Astrophysical Phenomena · Physics 2022-09-27 Guang-Yao Zhou , Zhao-Huan Yu , Qiang Yuan , Hong-Hao Zhang

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

Observations of cosmic ray electrons have made great strides in the last decade and direct observations of the all-electron flux as well as separate electron and positron spectra are now available up to ~ 1 TeV. In this invited contribution…

High Energy Astrophysical Phenomena · Physics 2022-11-30 Philipp Mertsch

We combine the data from PAMELA and FERMI-LAT cosmic ray experiments by introducing a simple sum rule. This allows to investigate whether the lepton excess observed by these experiments is charge symmetric or not. We also show how the data…

High Energy Physics - Phenomenology · Physics 2015-05-28 Isabella Masina

The AMS-02 collaboration has recently released data on the positron fraction $e^+/(e^-+e^+)$ up to energies of about 350 GeV. If one insists on interpreting the observed excess as a dark matter signal, then we find it is best described by a…

High Energy Physics - Phenomenology · Physics 2013-05-06 Andrea De Simone , Antonio Riotto , Wei Xue

The unexpected energy spectrum of the positron/electron ratio is interpreted astrophysically, with a possible exception of the 100-300 GeV range. The data indicate that this ratio, after a decline between $0.5-8$ GeV, rises steadily with a…

High Energy Astrophysical Phenomena · Physics 2016-10-11 M. A. Malkov , P. H. Diamond , R. Z. Sagdeev

Can we learn about New Physics with astronomical and astro-particle data? Understanding how this is possible is key to unraveling one of the most pressing mysteries at the interface of cosmology and particle physics: the fundamental nature…

High Energy Physics - Phenomenology · Physics 2017-02-22 Stefano Profumo

The recent positron excess observed in the PAMELA satellite experiment strengthens previous experimental findings. We give here an analysis of this excess in the framework of the Stueckelberg extension of the standard model which includes…

High Energy Physics - Phenomenology · Physics 2009-03-24 Daniel Feldman , Zuowei Liu , Pran Nath

The excess in the positron fraction reported by the PAMELA collaboration has been interpreted as due to annihilation or decay of dark matter in the Galaxy. More prosaically, it has been ascribed to direct production of positrons by nearby…

High Energy Astrophysical Phenomena · Physics 2009-09-02 Philipp Mertsch , Subir Sarkar

Nearby pulsars within $\sim1\,{\rm kpc}$ are considered to be possible sources of 10-500 GeV cosmic-ray positron excess measured by PAMELA and AMS-02. A TeV halo around Geminga is detected by HAWC, and the measurements of its surface…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Yu Meng , Yun-Feng Liang , Ben-Yang Zhu , Xiao-Na Sun , En-Wei Liang
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