Search for Spatial and Temporary Variations of Galactic Cosmic Ray Positrons in PAMELA Experiment

Mikhailov, V. V; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Malakhov, V. V.; Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, Roberto; Boezio, M.; Bogomolov, E. A.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, Alessandro; Cafagna, F.; Campana, D.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; De Santis, C.; De Simone, N.; Di Felice, V.; Formato, V.; Koldobskiy, S.; Krutkov, S.; Kvashnin, A.; Leonov, A.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Merge, M.; Mocchiutti, E.; Monaco, Alfonso; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.

doi:10.1016/j.phpro.2015.09.246

The PAMELA experiment is gathering data since 2006 on board the Resurs DK1 satellite (orbit with inclination 70.4°, the altitude 350-600 km). The instrument consists magnetic spectrometer, silicon-tungsten imaging electromagnetic calorimeter, neutron detector and shower scintillator that gives possibility to measure electron and positron fluxes over wide energy range from hundreds MeVs to hundreds GeVs. Results of the experiment indicate the presence of a large flux of positron with respect to electrons in the CR spectrum above 10 GeV. This excess might be originated through dark matter annihilation or in local astrophysical objects such as pulsars producing possible spatial and season variations. Electron and positron events have been analyzed searching for spatial and temporal variations from June 2006 till January 2014.