The all-particle cosmic ray energy spectrum measured with HAWC

TL;DR

This paper presents an updated measurement of the all-particle cosmic ray energy spectrum using HAWC data, extending the energy range up to 1 PeV and confirming a knee-like feature at tens of TeV.

Contribution

It extends the cosmic ray energy spectrum measurement with HAWC data up to 1 PeV, providing new insights into high-energy cosmic ray features.

Findings

Confirmed the knee-like feature at tens of TeV

Extended the spectrum measurement up to 1 PeV

Validated the use of unfolding method with QGSJET-II-04 model

Abstract

Thanks to recent technological development, a new generation of cosmic ray experiments have been developed with more sensitivity to study these particles in the primary energy interval from 10 TeV to 1 PeV, such as HAWC. Due to its design and high altitude, the HAWC gamma-ray and cosmic ray observatory can provide a bridge between the data from direct and indirect cosmic ray detectors. In 2017 the HAWC collaboration published its first result on the total energy spectrum of cosmic rays, which covers the range from 10 to 500 TeV. This work updates the previous result by extending the energy interval of the measured all-particle cosmic-ray energy spectrum up to 1 PeV. The energy spectrum was obtained from the analysis of two years of HAWC's data using an unfolding method. We employed the QGSJET-II-04 model for the energy calibration and the spectrum reconstruction. The results confirm the presence of a knee like feature at tens of TeV, as previously reported by the HAWC collaboration in 2017.