The effect of near-earth thunderstorm electric field on the rate of the shower events detected by ARGO-YBJ

The ARGO-YBJ detector was operated for 5 years at the YangBaJing Cosmic Ray Observatory (4300 m a. s. l., Tibet, China). The high altitude location and the high granularity of the "full coverage" detector (central carpet with an active area of ∼ 93 %), allow a detailed space-time reconstruction of cosmic ray showers, making ARGO-YBJ well suitable to study the effects of thunderstorm electric field on the shower development in atmosphere. An accurate Monte Carlo simulation has been implemented to interpret the ARGO-YBJ data. CORSIKA is used to simulate the evolution and properties of extensive air showers in atmosphere. The G4argo code takes into account the response of the ARGO-YBJ detector. The correlation between the reconstructed shower event rate and the near-earth thunderstorm electric field has been studied in detail. We found that the variation of the shower rate depends on the strength and polarity of the electric field, and is also highly dependent on the zenith angle of the primary cosmic ray. These results could be helpful in understanding the effects of the electric fields on cosmic rays, and provide important information for other cosmic ray studies with ground-based detectors (such as LHAASO).