Kookhyun Kang ; on behalf of the Belle-II SVD Collaboration

13 January 2023

Abstract: Belle II is an experiment taking data at an asymmetric energy e+e- collider, SuperKEKB, which is operated at the Υ(4S) resonance energy. The Belle II vertex detector is composed of an inner two-layer pixel detector (PXD) and an outer four-layer double-sided strip detector (SVD). A deep knowledge of the system has been gained since the start of the SVD operation in 2019 by assessing the high-quality and stable reconstruction performance of the detector with excellent performance and good stability for hit efficiency and signal-to-noise ratio. The good cluster-position resolution is in reasonable agreement with the expectations. The Belle II event time obtained from CDC is replaced with a new method to allow faster calculation based on the SVD event T0 while achieving the same time resolution. Currently the average occupancy of the SVD is still < 0.5%, which is well below the limit estimated from tracking performance study. The radiation damage effects on the sensor current and strip noise are measured, and we confirm they do not significantly degrade the SVD performance.

Keyword(s): Silicon strip detector ; Vertex detector ; Tracking detector ; Belle II ; Radiation damage
Note: Proceedings of the 31st International Workshop on Vertex Detectors