PAMELA is a satellite-borne experiment which is taking data since 2006. It consists of a permanent magnetic spectrometer, an electromagnetic calorimeter, a time-of-flight system, a neutron detector and an anticoincidence system. Positrons are a probe of the local galactic environment, allowing secondary production and propagation models to be tested. Exotic processes such as dark matter particle annihilations may also produce an excess of positrons at high energies. Combining information from different detectors and in particular from the calorimeter, positrons can be identified from the overwhelming proton background. The anomalous positron fraction measured by the PAMELA Collaboration in 2009 [1] covers an energy range up to 100 GeV. A new approach for positron identification is described, based on a combination of shower profile variables in the calorimeter, with the aim of extending the positron fraction analysis up to ∼ 300 GeV.
Positron identification study with the PAMELA calorimeter / Rossetto, L.; Adriani, O.; Barbarino, G.C.; Bazilevskaya, G.A.; Bellotti, R.; Boezio, M.; Bogomolov, E.A.; Bongi, M.; Bonvicini, V.; Borisov, S.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; Consiglio, L.; De Pascale, M.P.; De Santis, C.; De Simone, N.; Di Felice, V.; Galper, A.M.; Gillard, W.; Grishantseva, L.; Jerse, G.; Karelin, A.V.; Kheymits, M.D.; Koldashov, S.V.; Krutkov, S.Y.; Kvashnin, A.N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Mayorov, A.G.; Menn, W.; Mikhailov, V.V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Nikonov, N.; Osteria, G.; Palma, F.; Papini, P.; Pearce, M.; Picozza, P.; Pizzolotto, C.; Ricci, M.; Ricciarini, S.B.; Sarkar, R.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y.I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S.A.; Yurkin, Y.T.; Wu, J.; Zampa, G.; Zampa, N.; Zverev, V.G.. - ELETTRONICO. - 6:(2011), pp. 35-38. (Intervento presentato al convegno 32nd International Cosmic Ray Conference, ICRC 2011 tenutosi a Beijing, chn nel 2011) [10.7529/ICRC2011/V06/0667].
Positron identification study with the PAMELA calorimeter
ADRIANI, OSCAR;BONGI, MASSIMO;
2011
Abstract
PAMELA is a satellite-borne experiment which is taking data since 2006. It consists of a permanent magnetic spectrometer, an electromagnetic calorimeter, a time-of-flight system, a neutron detector and an anticoincidence system. Positrons are a probe of the local galactic environment, allowing secondary production and propagation models to be tested. Exotic processes such as dark matter particle annihilations may also produce an excess of positrons at high energies. Combining information from different detectors and in particular from the calorimeter, positrons can be identified from the overwhelming proton background. The anomalous positron fraction measured by the PAMELA Collaboration in 2009 [1] covers an energy range up to 100 GeV. A new approach for positron identification is described, based on a combination of shower profile variables in the calorimeter, with the aim of extending the positron fraction analysis up to ∼ 300 GeV.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.