Energy Spectrum of Cosmic Protons and Helium Nuclei by a Hybrid Measurement at 4300 m a.s.l
astro-ph.HE
/ Authors
B. Bartoli, P. Bernardini, X. J. Bi, I. Bolognino, P. Branchini, A. Budano, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, R. Cardarelli
and 91 more authors
S. Catalanotti, S. Z. Chen, T. L. Chen, P. Creti, S. W. Cui, B. Z. Dai, A. D'Amone, Danzengluobu, I. De Mitri, B. D'Ettorre Piazzoli, T. Di Girolamo, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Hu, Hongbo Hu, M. Iacovacci, R. Iuppa, H. Y. Jia, Labaciren
/ Abstract
The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured, below the so-called "knee", by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range (100 TeV - 700 TeV). The observed energy spectrum is compatible with a single power law with index gamma=-2.63+/-0.06.