A measurement of the all-particle energy spectrum of cosmic rays from 1013 to 1015eV using HAWC

Abstract

We report the total energy spectrum of cosmic rays in the energy interval from $10\text{TeV}$ to $1\text{PeV}$, which lies in the energy region where both direct and indirect cosmic ray experiments overlap. The all-particle spectrum was obtained from an unfolding analysis of 5.3 years of data collected with the High Altitude Water Cherenkov (HAWC) observatory for zenith angles smaller than or equal to 35°. The study was carried out in the framework of the QGSJET-II-04 hadronic interaction model. The measured spectrum confirms the presence of a knee-like feature at tens of TeV. In our analysis, the position of this softening is found at $40.2\pm 1.0$(stat.)${}_{-6.4}^{+6.2}$(sys.)$\mathrm{TeV}$. The measured spectral indices before and after the break are ${\gamma }_1=-2.53\pm 0.01$(stat.)${}_{-0.05}^{+0.04}$(sys.) and ${\gamma }_2=-2.71\pm 0.01$(stat.)${}_{-0.04}^{+0.03}$(sys.), respectively.