000004567 001__ 4567
000004567 005__ 20241016132840.0
000004567 037__ $$aBELLE2-CONF-PROC-2024-024
000004567 041__ $$aeng
000004567 100__ $$aA. Kumar et al.
000004567 245__ $$aUpgrade of the Belle II Vertex Detector with monolithic active pixel sensors
000004567 260__ $$a$$c2024-10-16
000004567 300__ $$a6
000004567 500__ $$aThe second version of ICHEP 2024 proceedings.
000004567 520__ $$aThe Belle II experiment at the SuperKEKB accelerator in Japan is dedicated to exploring physics beyond the Standard Model by performing high-precision measurements of heavy-flavor processes. The SuperKEKB will undergo a major upgrade during a second long shutdown to achieve the target luminosity of 6$\times$10$^{35}$ cm$^{-2}$s$^{-1}$. The vertex detector is a critical component of Belle II, responsible for precise tracking and vertexing near to the interaction point. The current vertex detector will be upgraded to a fully pixelated vertex detector (VTX) based on Monolithic Active Pixel Sensors (MAPS) technology to enhance performance and address challenges from increasing luminosity. The VTX will consist of five layers of depleted MAPS sensor, called OBELIX, with radii from 14~mm to 140~mm and a material budget ranging from 0.2-0.8$\%$~X/X$_{0}$ per layer. The OBELIX sensor is derived from the TJ-Monopix2 sensor, originally developed under TowerJazz 180~nm for the ATLAS experiment. This paper discusses the design, implementation, and expected performance of the VTX, highlighting the technical advances brought by MAPS technology, which offer significant advantages in terms of material budget, radiation hardness, and spatial resolution. The motivation for this upgrade, the design considerations, and the expected performance improvements are analyzed.
000004567 8560_ $$fajit.kumar@iphc.cnrs.fr
000004567 8564_ $$uhttps://docs.belle2.org/record/4567/files/BELLE2-CONF-PROC-2024-024.pdf