[astroseminar at Sapienza] today at 15:00: Paolo Lipari

[Elia Battistelli]

Title: Interpretation of the cosmic ray positron and antiproton fluxes
Speaker:   Paolo Lipari
Institute: INFN, Sezione di Roma
Date: Monday, 27 February 2017
Time: 3:00pm
Location: Aula Conversi, Marconi Building, Dept. of Physics, Sapienza 
University

Abstract:
The spectral shape of cosmic ray positrons and antiprotons has been 
accurately measured in the broad kinetic energy range 1-350 GeV. In the 
higher part of this range (E > 30 GeV)  the positron/antiproton flux 
ratio has the approximately constant value 2.04+-0.04, that is 
consistent with being equal to the ratio e+/pbar calculated for the 
conventional mechanism of production, where the antiparticles are 
created as secondaries in the inelastic interactions of primary cosmic 
rays with interstellar gas.  The positron/antiproton ratio at lower 
energy is significantly higher but in the entire energy range 1-350 GeV, 
the flux ratio is consistent with being equal to ratio of the production 
rates in the conventional mechanism, since the low energy antiprotons 
production is kinematically suppressed. These results strongly suggest 
that cosmic ray positrons and antiprotons have a common origin as 
secondaries in hadronic interactions. This conclusion has broad 
implications for the astrophysics of cosmic rays in the Galaxy.

web: https://agenda.infn.it/conferenceDisplay.py?confId=12835