Ring Imaging Cherenkov detectors for the next generation of flavor physics experiments

The present-day experiments in particle physics are searching for deviations from the Standard Model of elementary particles. In this search, the study of possible deviations from lepton flavour universality is currently one of the hottest topics in high-energy physics. The two most crucial flavour physics experiments, currently under operation, are Belle II at the SuperKEKB collider of KEK, Tsukuba, Japan, and LHCb at the Large Hadron Collider of the European Organization for Nuclear Research – CERN, Geneva. To further investigate the observed phenomena, a substantial increase in the data sample size is planned in the next generation of experiments with a much higher interaction rate. For operation in such an environment, the upgrade of the particle detectors is necessary. A reliable charged particle identification is of paramount importance in both experiments, and Ring Imaging Cherenkov detectors are employed for this task. To keep the identification capabilities or even enhance them in the new challenging environment, we are studying the upgrade of both experiments' ring imaging Cherenkov detectors. In addition to necessary changes in the detector geometry, a photon sensor capable of detecting single photons with high efficiency and high position resolution will have to be employed. One of the few candidates is silicon photomultipliers. We will have to solve several problems for a successful deployment in such hostile environments in both detectors. We will have to decrease the dark count rate and the sensitivity of sensors to neutron irradiation, increase the sensor granularity, and adjust the readout electronics. In the scope of the research project, we will, by systematic studies, develop a sensor module that could be used as the photon detector in both experiments. We will determine the optimal operation parameters and test them in the Ring Imaging Cherenkov prototype.