Speaker
Description
The origin of the knee in the all-particle energy spectrum is still unknown. One of the most important issues in cosmic ray physics is the measurement of the knee in the energy spectrum of individual components. LHAASO is made up of three detector arrays, which are the wide field-of-view Cherenkov telescope array (WFCTA), the kilometer square array (KM2A) and the water Cherenkov detector array (WCDA). The three detector arrays can achieve hybrid observation, so several Extensive Air Shower (EAS) observables sensitive to mass compositions can be measured simultaneously. In this work, the data between November 2020 and March 2021 with the shower core located in KM2A are used to obtain the proton energy spectrum. By using ROOT-TMVA package in combination with various component-sensitive parameters, we selected proton events with purity above 90 percent. The uncertainties from the proton selection, absolute energy determination, and interaction models will be discussed.
