Measurement of the Cosmic Ray spectra by the ARGO-YBJ experiment

Abstract

Exploiting the features and location at high altitude (the Cosmic Ray Observatory of Yangbajing in Tibet, China, at about 4,300 m a.s.l.) of the ARGO-YBJ detector, the study of several aspects concerning cosmic ray physics in the primary energy region 1012–1016 eV has been performed. Here, the preliminary results of the measurement of all-particle and light-component (i.e. protons and helium nuclei) energy spectra between few tens TeV and ∼5 PeV will be reported, as obtained from the data of RPC (Resistive Plate Chamber) analog charge readout. The study of such energy region is particularly important to better understand the so called knee of the energy spectrum and its origin, as well as for a powerful cross-check among very different experimental techniques, like balloon/space-borne spectrometers and surface air shower detectors. It also allows to test the hadronic interaction models currently used for investigating particle and cosmic ray physics up the highest energies. Finally, the precise measurements of the cosmic ray energy spectrum and composition make possible a more reliable estimation of the atmospheric neutrino flux, which is crucial for any extra-terrestrial neutrino search.