Positron annihilation as a cosmic ray probe

New limits on dark matter annihilation from AMS cosmic ray positron data

New limits on dark matter annihilation from Alpha Magnetic Spectrometer cosmic ray positron data.

The Alpha Magnetic Spectrometer experiment onboard the International Space Station has recently provided cosmic ray electron and positron data with unprecedented precision in the range from 0.5 to 350 GeV. The observed rise in the positron fraction at energies above 10 GeV remains unexplained, with proposed solutions ranging from local pulsars to TeV-scale dark matter. Here, we make use of this...

Supplemental Material to ‘New limits on dark matter annihilation from AMS cosmic ray positron data’

Lars Bergström, Torsten Bringmann, Ilias Cholis, Dan Hooper, 4 and Christoph Weniger The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden II. Institute for Theoretical Physics, University of Hamburg, Luruper Chausse 149, DE-22761 Hamburg, Germany Center for Particle Astrophysics, Fermi National Accelerator Laborator...

Positron annihilation as a probe of electronic density in the two-dimensional conductor 1T-TAS2

2014 Tantalum disulfide is a layered compound with quasi-two-dimensional electronic conduction. The particular topology of the 2D-Fermi surface causes the onset of charge density waves which drive a metal-to-insulator phase transition in two steps. Three standard positron annihilation techniques have been used to sample the electronic density and momentum distributions in this compound as a fun...

Microquasars as sources of positron annihilation radiation

We consider the production of positrons in microquasars, i.e. X-ray binary systems that exhibit jets frequently, but not continuously. We estimate the production rate of positrons in microquasars, both by simple energy considerations and in the framework of various proposed models. We then evaluate the collective emissivity of the annihilation radiation produced by Galactic microquasars and we ...