Cosmic Ray Positrons at High Energies: A New Measurement
Astrophysics
2012-08-27 v1
Abstract
We present a new measurement of the cosmic-ray positron fraction e+/(e+ + e-) obtained from the first balloon flight of the High Energy Antimatter Telescope (HEAT). Using a magnet spectrometer combined with a transition radiation detector, an electromagnetic calorimeter, and time-of-flight counters we have achieved a high degree of background rejection. Our results do not indicate a major contribution to the positron flux from primary sources. In particular, we see no evidence for the significant rise in the positron fraction at energies above ~10 GeV previously reported.
Cite
@article{arxiv.astro-ph/9505141,
title = {Cosmic Ray Positrons at High Energies: A New Measurement},
author = {HEAT Collaboration},
journal= {arXiv preprint arXiv:astro-ph/9505141},
year = {2012}
}
Comments
14 pages, 3 figures, tarred-compressed-uuencoded-postscript file; heatprl_preprint.tar_z (227 kbytes); Physical Review Letters, in print