Speaker
Dr
Carmelo Sgro'
(INFN-Pisa)
Description
With a precise measurement of the combined Cosmic-Ray electron and positron spectrum,
the Fermi Large Area Telescope (LAT) has proven to be an excellent electron detector.
Being a purely calorimetric experiment, the LAT is not capable to directly
distinguish particle charge. However, we can exploit the Earth's magnetic field to
effectively separate negatively and positively charged particles.
With the aid of a precise tabulation of the geomagnetic field, we are able to predict
trajectories of particles in this field and use this information to discriminate
between positrons and electrons. In this talk we present the details of this analysis
together with the preliminary results on the positron and electron spectra for
energies greater than 20 GeV. The derived positron fraction will be also discussed.
Primary author
Dr
Carmelo Sgro'
(INFN-Pisa)
