Karim Trabelsi (Pôle Physique des Hautes Energies, Team B-factories) has just been elected spokesperson for Belle-II. His appointment will be effective from June 2023. The Belle-II experiment is installed at the e+e- superKEKB collider at KEK in Japan, the brightest in the world in its category: SuperKEKB has in fact reached an instantaneous luminosity of 4.7x1034/cm2/s is more than twice the KEKB record.
The major challenge of the Belle-II experiment is to highlight signs of new physics, not described by the standard model of particle physics. For example, it is looking for the existence of hypothetical dark matter particles or lepto-quarks which would explain the recent anomalies observed in the decays of B mesons. The Belle-II precision detector is indeed dedicated to the very fine characterization of B mesons, charmed hadrons or tau leptons, to shed light on deviations in the observables of rare decays or the discovery of forbidden decays in the Standard Model, which would be a sign of new physics.
Since the start of its data collection, in the spring of 2019, Belle-II has been able to accumulate 430 fb-1 of data, which is the equivalent of the statistics of the previous generation of factory at B such as Belle (Japan) or Babar (United-States). This data sample, already calibrated and reprocessed, will be used for the Belle-II analyzes of 2023. From June 2022 until the end of 2023, a long shutdown will allow the replacement of the two pixel layers. Besides IJCLab, two other IN2P3 laboratories are involved in Belle-II: CPPM (Marseille) and IPHC (Strasbourg).
To find out more, the portrait of Karim Trabelsi (published in September 2019) and the description of the Belle-II experience (PDF).