The Silicon Vertex Detector of the Belle II Experiment

Sato, Yo; Adamczyk, K.; Aggarwal, L.; Aihara, H.; Aziz, T.; Bacher, S.; Bahinipati, S.; Batignani, G.; Baudot, J.; Behera, P. K.; Bettarini, S.; Bilka, T.; Bozek, A.; Buchsteiner, F.; Casarosa, Giulia; Corona, L.; Das, S.; Dujany, G.; Finck, C.; Forti, F.; Friedl, M.; Gabrielli, A.; Gobbo, B.; Halder, S.; Hara, K.; Hazra, S.; Higuchi, T.; Irmler, C.; Ishikawa, A.; Jin, Y.; Kaleta, M.; Kaliyar, A. B.; Kandra, Jakub; Kang, K. H.; Kodyš, P.; Kohriki, T.; Kumar, R.; Lalwani, K.; Lautenbach, K.; Leboucher, R.; Lee, S. C.; Libby, J.; Martel, L.; Massaccesi, L.; Mohanty, G. B.; Mondal, S.; Nakamura, K. R.; Natkaniec, Z.; Onuki, Y.; Otani, F.; Paladino, A.; Paoloni, E.; Park, H.; Polat, L.; Rao, K. K.; Ripp-Baudot, I.; Rizzo, G.; Schwanda, C.; Serrano, J.; Shimasaki, T.; Suzuki, J.; Tanaka, S.; Tanigawa, H.; Tenchini, F.; Thalmeier, R.; Tiwary, R.; Tsuboyama, T.; Uematsu, Y.; Vitale, L.; Wang, Z. M.; Webb, J.; Werbycka, O.; Wiechczynski, J.; Yin, H.; Zani, Laura

doi:10.22323/1.449.0550

Abstract

The Belle II experiment started data-taking in March 2019.
The silicon vertex detector (SVD), part of the Belle II tracking system, has been operating smoothly and reliably.
The data quality has been confirmed through various metrics such as a good signal-to-noise ratio and precise spatial resolution.
The radiation damage effects have been continuously monitored, showing good agreement with our expectations. So far, no harmful impact due to the radiation damage on the detector performance has been observed. Additionally, the radiation tolerance of SVD sensors for future high-luminosity runs has been examined in a new irradiation campaign.
In the high-luminosity runs, an increase in hit-occupancy is also expected due to the beam-induced backgrounds. To enhance the robustness of offline software in a high-background environment, new algorithms of background suppression using hit-time information have been developed.