Speaker
Description
We present a comprehensive overview of the construction, operation, and performance of the imaging Time-of-Propagation (TOP) detector of the Belle II experiment at the SuperKEKB e+e− collider. Situated in the central barrel region of Belle II, the TOP detector is a critical component for the charged particle identification (PID). It leverages Cherenkov radiation, which is produced as charged particles pass through the fused silica (quartz) bars. The Cherenkov photons are transported to the ends of the bars via total internal reflection. The detector's innovative design allows for precise measurements that enable excellent particle discrimination. One end of each quartz bar is instrumented with finely segmented micro-channel-plate photomultiplier tubes (MCP-PMTs) to capture the light signal. A mirror is attached to the opposite end, which reflects any photons back toward the instrumented end, thereby maximizing the light collection efficiency. By measuring both the photon propagation times and hit positions, which are directly related to the Cherenkov angle, the TOP detector can effectively distinguish between charged pions, kaons, and protons with momenta up to approximately 4 GeV/c. Our PID performance analysis is based on over 400 fb⁻¹ of Belle II data, demonstrating the TOP detector's capabilities. This work highlights its successful operation in a high-luminosity environment and its vital contribution to the physics program of the Belle II experiment.
| Position | Assistant Professor |
|---|---|
| Affiliation | Indian Institute of Technology Hyderabad |
| Country | India |