The Belle II vertex detector integration

Abstract The Belle II experiment comes with a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e + e − collider with energies tuned to ϒ ( 4 S ) resonance s = 10 . 588  GeV. The accelerator has successfully completed the first phase of commissioning in 2016 and the first electron–positron collisions in Belle II took place in April 2018. Belle II features a newly designed silicon vertex detector based on DEPFET pixel and double-sided strip layers. Currently, a subset of the vertex detector is installed (Phase 2 of the experiment). Installation of the full detector (Phase 3) will be completed by the end of 2018. This paper describes the Phase 2 arrangement of the Belle II silicon vertex detector, with focus on the interconnection of detectors and their integration with the software framework of Belle II. Alignment issues are discussed based on detector simulations and first acquired data.