The Imaging Time-of-Propagation Detector at Belle II

Abstract

We report on the construction, operation, and performance of the Time-of-Propagation detector with imaging used for the Belle II experiment running at the Super-KEKB $e^{+}{e}^{-}$ collider. This detector is located in the central barrel region and uses Cherenkov light to provide particle identification among hadrons. The Cherenkov light is radiated in highly polished bars of synthetic fused silica (quartz) and transported to the ends of the bars via total internal reflection. One bar end is instrumented with finely segmented micro-channel-plate photomultiplier tubes to record the light, while the other end has a mirror attached to reflect the photons back to the instrumented end. Both the propagation times and hit positions of the Cherenkov photons are measured; these depend on the Cherenkov angle and together provide good discrimination among charged pions, kaons, and protons with momenta up to around 4 GeV/$c$. To date, the detector has been used to record and analyze almost 600 fb${}^{-1}$ of Belle II data.

arXiv comment46 pages, 48 figures, 4 tables. Version 2: as published in Nuclear Instruments and Methods in Physics Research A

References in corpus (11)

• sPlot: a statistical tool to unfold data distributions
• SuperKEKB Collider
• Time-of-Propagation Cherenkov counter for particle identification
• Lifetime-Extended MCP-PMT
• Optical Properties of the DIRC Fused Silica Cherenkov Radiator
• Test Result of Time-Of-Propagation Cherenkov Counter
• Front-end electronic readout system for the Belle II imaging Time-Of-Propagation detector
• An imaging time-of-propagation system for charged particle identification at a super B factory
• PCI-express based high-speed readout for the BelleII DAQ upgrade
• The trigger slow control system of the Belle II experiment
• The TOP counter and determination of bunch-crossing time at Belle II

Cited by in corpus (1)

• First measurements of the branching fractions for the decay modes ${\Xi }_c^0\to \Lambda \eta$ and ${\Xi }_c^0\to \Lambda {\eta }^{\prime }$ and search for the decay ${\Xi }_c^0\to \Lambda {\pi }^0$ using Belle and Belle II data