The paper titled "The Imaging Time-of-Propagation Detector at Belle II" was published in Nuclear Instruments and Methods in Physics Research Section A, involving Prof. Toru Iijima, associate Prof. Kenji Inami, and N-lab members.

In this study, we reported on the construction, operation, and performance of the Time-of-Propagation detector with ring-imaging used in the SuperKEKB/Belle II experiment. This detector is located in the barrel region and uses Cherenkov light for hadron particle identification. The Cherenkov light is radiated in synthetic fused silica bars and transported to the ends of the bars via total internal reflection. One end of each bar is instrumented with micro-channel-plate photomultiplier tubes (MCP-PMTs) to detect the light, while the other end has a mirror attached to reflect the photons back to the MCP-PMTs. Both the propagation times and hit positions of the Cherenkov photons are measured. Because these quantities depend on the Cherenkov angle, they 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.

Paper information:
H. Atmacan, et al., "The Imaging Time-of-Propagation Detector at Belle II"
[Nucl. Instrum. Methods Phys. Res. A, 1080, 170627 (2025). DOI:10.1016/j.nima.2025.170627]