The Belle II experiment is located at the SuperKEKB accelerator at KEK in Japan, the most powerful of its kind in the world. Luminosity in particle physics is a measure of how many particle collisions take place in an accelerator experiment within a certain period of time. SuperKEKB has achieved an instantaneous luminosity of 4.7 x 1034 cm-2s-1, more than twice the previous KEKB record. Technologies relevant to a future Higgs factory at CERN are also being tested at the SuperKEKB accelerator.
The main goal of the Belle II experiment is to discover signs of new physics that are not described by the Standard Model of particle physics. For example, it searches for the existence of hypothetical dark matter particles or leptoquarks that could explain the recently observed anomalies in the decays of B mesons. The Belle II detector is specifically designed for the precise characterization of B mesons, charm hadrons, and tau leptons to identify deviations in the observables of rare decays or the discovery of decays forbidden in the Standard Model, which would indicate new physics. The physics program also includes the study of exotic hadron states and the precise measurement of processes that are important for understanding the anomalous magnetic moment of the muon.
Since data collection began in the spring of 2019, Belle II has accumulated 430 fb-1 of data, which is approximately equivalent to the statistics of the previous generation of B factories such as Belle (Japan) and BaBar (USA). These already calibrated and reprocessed data will be used for Belle II analyses in 2024. From June 2022 to the end of 2023, an extended shutdown was used to install a new pixel detector. Members of the University of Bonn and the Research and Technology Center for Detector Physics were significantly involved in the development and installation in Japan.
As spokesperson, Prof. Dr. Bernlochner assumes a key role in coordinating the scientific and technical activities of the collaboration. “The coming years will be particularly exciting for the Belle II experiment,” says Bernlochner. “With the ongoing data collection and future analyses, Belle II will venture into unexplored areas - in search of new processes and particles that could change our understanding of the fundamental building blocks of matter.”
We congratulate Prof. Dr. Florian Bernlochner on his election and look forward to the scientific advances and discoveries that will be achieved under his leadership at Belle II.
The Belle II experiment plays a central role in the Excellence Cluster "Color meets Flavor" by investigating both the weak interaction ("flavor") and the strong interaction ("color") in decays of B mesons and charm hadrons. The aim of the Cluster of Excellence CmF is to identify new fundamental physical phenomena through the interplay of the strong and weak interactions. With their world-leading expertise in the physics of strong and weak interactions, the Universities of Bonn, Dortmund and Siegen and the Forschungszentrum Jülich complement each other in a unique way to advance this field. Belle II is a key experiment that bridges the gap between different research methods and energy scales.
