scispace - formally typeset
Open AccessJournal ArticleDOI

Cosmic-Ray Positron Energy Spectrum Measured by PAMELA

TLDR
The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy.
Abstract
Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24 500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.

read more

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI

Galactic center GeV gamma-ray excess from dark matter with gauged lepton numbers

TL;DR: In this paper, a leptonic dark matter annihilates into the standard model leptons, μ + μ − and τ + τ −, by the interaction of the gauged lepton number U(1)Lμ−Lτ and fits the observed excess.
Journal ArticleDOI

Supersymmetric Resonant Dark Matter: a Thermal Model for the AMS-02 Positron Excess

TL;DR: In this paper, a thermal dark matter model with annihilation mediated by a resonance was proposed to explain the positron excess observed by PAMELA, Fermi-LAT and AMS-02, while satisfying constraints from cosmic microwave background (CMB) measurements.
Journal ArticleDOI

Local fading accelerator and the origin of TeV cosmic ray electrons

TL;DR: In this article, it was shown that a local, continuous (on timescales of $\ensuremath{\sim}{10}^{5}\text{ }\text{ }, }\mathrm{yr}$) but fading electron accelerator, with a characteristic decay time of
Journal ArticleDOI

Positrons from primordial black hole microquasars and gamma-ray bursts

TL;DR: In this paper, the capture of small sublunar mass primordial black holes (PBHs) by compact stars, white dwarfs or neutron stars, can lead to distinct short gamma-ray bursts (sGRBs) as well as microquasars (MQs).
Journal ArticleDOI

Phenomenology of scotogenic scalar dark matter

TL;DR: In this paper, the authors reexamine the minimal Singlet $+$$ Triplet Scotogenic Model, where dark matter is the mediator of neutrino mass generation, and perform a full numerical analysis of the signatures expected at dark matter as well as collider experiments.
References
More filters
Journal ArticleDOI

Random Forests

TL;DR: Internal estimates monitor error, strength, and correlation and these are used to show the response to increasing the number of features used in the forest, and are also applicable to regression.
Journal ArticleDOI

Geant4—a simulation toolkit

S. Agostinelli, +126 more
TL;DR: The Gelfant 4 toolkit as discussed by the authors is a toolkit for simulating the passage of particles through matter, including a complete range of functionality including tracking, geometry, physics models and hits.
Journal ArticleDOI

Machine learning

TL;DR: Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis.
Related Papers (5)

First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV.

M. Aguilar, +347 more

Measurement of Separate Cosmic-Ray Electron and Positron Spectra with the Fermi Large Area Telescope

Markus Ackermann, +158 more

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

M. Aguilar, +294 more