The cosmic ray proton plus helium energy spectrum measured by the ARGO-YBJ experiment in the energy range 3-300 TeV

TL;DR

This paper reports on the measurement of the cosmic ray proton plus helium energy spectrum in the 3-300 TeV range using the ARGO-YBJ air shower detector, demonstrating ground-based measurement capabilities in this energy region.

Contribution

First ground-based measurement of the cosmic ray proton plus helium spectrum in the TeV range with high accuracy using the ARGO-YBJ detector.

Findings

Spectral index measured as -2.64 ± 0.01

Spectrum measured in the 3-300 TeV range

Demonstrates ground-based measurement of light elements

Abstract

The ARGO-YBJ experiment is a full-coverage air shower detector located at the Yangbajing Cosmic Ray Observatory (Tibet, People's Republic of China, 4300 m a.s.l.). The high altitude, combined with the full-coverage technique, allows the detection of extensive air showers in a wide energy range and offer the possibility of measuring the cosmic ray proton plus helium spectrum down to the TeV region, where direct balloon/space-borne measurements are available. The detector has been in stable data taking in its full configuration from November 2007 to February 2013. In this paper the measurement of the cosmic ray proton plus helium energy spectrum is presented in the region 3-300 TeV by analyzing the full collected data sample. The resulting spectral index is $\gamma = -2.64 \pm 0.01$. These results demonstrate the possibility of performing an accurate measurement of the spectrum of light elements with a ground based air shower detector.