New measurements from the PAMELA satellite of the cosmic ray electron and positron spectra are presented. Electrons were selected from 20 to 625 GeV and positrons from 20 to 200 GeV. This is the largest energy range covered by any cosmic ray experiment to date, and the first time that electrons above 50 GeV have been identified in cosmic rays. Details of the selection process are presented as are the methods utilized for the removal of proton contamination in both the electron and positron samples. The absolute fluxes of electrons and positrons are in agreement with previous PAMELA results when used to produce the positron fraction e+e-+e+ for comparison. This result is at odds with standard models of positron production and propagation in the interstellar medium and provides further evidence for the necessity of a primary source of cosmic ray positrons in the Solar neighborhood.
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- Physics, Astrophysics;Physics, Astronomy and Astrophysics;Physics, Elementary Particles and High Energy