Speaker
Description
The TA×4 experiment, which has been ongoing since a portion of the detectors were newly installed in 2019, aims to reveal the origin of UHECRs by expanding the detection area of the TA experiment by a factor of four and increasing the number of observed events. In the analysis with the surface detector (SD) of the TA×4 experiment, the reconstruction method has already been established for zenith angles up to 55 degrees. By extending this method to larger zenith angles, the number of events is expected to increase further. Using an enhanced method, we extended the energy estimation table generated from Monte Carlo simulations to zenith angles of up to 70 degrees. We also compared the results from observed and simulated data for each parameter obtained using the extended reconstruction method and confirmed no significant discrepancies between them. Furthermore, we measured the energy spectrum, including events with large zenith angles, based on three years of observed data.
