Grant: Subatomic Physics Envelope - Project

Belle-II will probe the flavour sector of particle physics at the high-luminosity SuperKEKB e+e- collider, located at the KEK laboratory in Japan. Physics operations will start in late 2016, with the goal of collecting by 2022 thirty times the combined integrated luminosity of the two previous generation B-factories, PEP-II at SLAC and KEKB at KEK. This precision-frontier facility will open an exciting window on new energy scales beyond the reach of existing colliders, including the LHC, by virtue of quantum loop corrections that are sensitive to very massive, and as yet undiscovered, particles. These hypothesized particles manifest themselves in precision measurements of processes involving bottom and charm quarks and tau leptons, such as CP violation and other asymmetries, rare decays, and processes that are forbidden within our current understanding of physics. If new physics is discovered at the LHC, the wide range of measurements possible at Belle-II will illuminate its flavour structure in ways that are not possible at a hadron collider. If new physics is not discovered at the LHC, Belle-II measurements will provide critical guidance towards beyond-the-standard-model theories by either discovering new phenomena and deviations from standard model expectations, or by excluding possible models of new physics. The funding requested will be used to fund personnel and travel to prepare for data collection and to complete the research and development on the upgrade of the Belle-II forward endcap calorimeter. Final design and construction of the upgraded calorimeter will commence during this period. Belle-II will start data taking with the thallium-doped caesium iodide ? CsI(Tl) ? scintillator calorimeter from Belle, outfitted with new digitizing and feature-extraction electronics. This calorimeter demonstrated very good performance for Belle, but as the luminosity of KEK-B increases, high occupancies from beam related backgrounds will cause significant deterioration of the performance of the forward endcap calorimeter. As its contribution to the Belle-II detector, the Canadian group is proposing to upgrade the high-occupancy regions of the forward endcap to pure CsI. Pure CsI is much faster than CsI(Tl), but has much lower light yield. These features, as well as the very large dynamic range and high bandwidth, requires these crystals to use new photosensors, amplifiers, digitizers, and feature-extraction algorithms. The Canadian group will take responsibility for all aspects of this project. In addition to designing and building the required hardware, the group will develop the associated software and algorithms for reconstruction code and feature extraction. The group is also participating in preparing the existing calorimeter for data taking. Graduate students will assist in the upgrade of the forward calorimeter electronics, and will perform the initial cosmic calibration. The group is studying backgrounds and shielding, and developing a thermal neutron detection system to verify these calculations during accelerator commissioning. The group will provide the Canadian share of computing resources and contribute to the development of cloud computing software for Belle-II. Students and research associates working on the Belle-II endcap calorimeter upgrade construction project also have the opportunity to analyze and publish on BABAR data. These HQP will have the unique experience of contributing to both a critical and innovative hardware construction project while also completing a particle physics analysis project.