Trigger efficiency measurement using e^+e^-→^+^- events at Belle II

Abstract

The Belle II detector was completed with the installation of a silicon vertex detector that covers most of the solid angle around the interaction region. In 2019 Physics Run before summer shutdown, 5.15 /fb of data were collected at a center of mass energy corresponding to the mass of the Y(4S). We present the measurement of the L1 and high-level trigger efficiencies at Belle IIusing the τ-pair events. The 1x3, 3x3, 1x5 and 1x1 τ-pair decay modes are considered. These measurements were performed using the e+e collision data recorded by Belle II during the early Phase III of data taking