Preliminary Cosmic Ray Results from the HAWC’s Eye Telescopes

The compact imaging air-Cherenkov telescope HAWC’s Eye was developed to operate with the High-Altitude Water Cherenkov Gamma-Ray Observatory (HAWC). The combination of both detection techniques in a hybrid configuration provides a significant improvement in energy and angular resolution, aiming for improved measurements of the cosmic ray composition above 10 TeV and contributing to the physics program of the observatory. Preliminary results of the first hybrid measurements of the cosmic ray spectrum are presented. After the first HAWC’s Eye telescope was brought to the HAWC site in 2017, a second telescope was successfully commissioned in 2019. Two measurement nights have since then recorded the data used in this analysis. The HAWC’s Eye events were successfully synchronized with the events recorded from the extensive air-shower array HAWC and further used to characterize the hybrid system. A complete simulation of the hybrid configuration was used to develop algorithms to reconstruct the energy and arrival direction of proton-induced air showers. Those algorithms were successfully applied to the measured cosmic ray events to verify the performance of the hybrid detection. The spectrum reconstructed with HAWC’s Eye is consistent with the spectrum reconstructed solely from the coincident HAWC data.