Positron fraction, electron and positron spectra measured by AMS-02

a-axis-projected electron-positron-momentum density and positron-annihilation spectra in YBa2Cu3O7-x.

Can Soft Glljon Effects Be Measured in Electron - Positron Annihilation ? *

The energy-energy correlation at large angles in +e e annihilation is calculated byresumming soft gluon contributions through two-loop level. The result is compared with experimental data. No agreement is obtained using a purely perturbative analysis. The relevance of nonperturbative effects at present energies is emphasized. (Submitted to Progress of Theoretical Physics Letters) * Work support...

Positron Fraction in the Cmssm ∗

A fit to the present cosmic ray positron fraction can be considerably improved, if in addition to the positron production by nuclear interactions in the universe the possible contribution from supersymmetric dark matter annihilation is taken into account. We scan over the complete SUSY parameter space of the Constrained Minimal Supersymmetric Model (CMSSM) and find that in the acceptable region...

Cosmic-ray Positron Fraction Measurement from 1 to 30 Gev with Ams-01

A measurement of the cosmic ray positron fraction e + /(e + + e −) in the energy range of 1–30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10 6 is reached by identifying converted bremsstrahlung photons emitted from positrons.

Electron/Positron Identification

This electron/positron identification variable summary will check our understanding of these particles’ behavior in the isolated Radiative Bhabha environment versus the highdensity hadronic environment of the CLEO detector.