TAx4 surface detectors data analysis

Abstract

The TAx4 experiment aims to understand UHECR by expanding the observation area of the TA experiment by a factor of 4 and increasing the statistics of UHECR events with energy greater than 1019 eV. TAx4 consists of newly installed Surface Detectors (SD) and Fluorescence Detectors (FD). The SD was only partially developed before the COVID pandemic and it currently operates with an area 2.5 times TA including the original TA area. The TAx4 SD array has been collecting data since April 2019, and data analysis is underway. In this paper, we will report on the comparison between Monte Carlo simulation and real data acquired by the TAx4 SD array and the preliminary energy spectrum of TAx4 SD array.