Kazuki Kojima presented Belle II research results at the 31st International Symposium on Lepton Photon Interactions at High Energies (Lepton Photon 2023) held in Melbourne, Australia, from July 17th to 21st. The presentation slide can be found at the following link.
In his report, he presented the first result of R(D*) measurement from the Belle II experiment, to which he made a major contribution. The experimental average of the R(D)-R(D*) values had been found to deviate from the Standard Model (SM) prediction by more than 3σ. This discrepancy could induce a violation of lepton flavor universality, indicating the existence of New Physics beyond the SM, and new measurements are required for further tests. Even with the new Belle II result in the average, the deviation is still observed to exceed 3σ. Please refer to the Heavy Flavor Average Group page for the latest world average of R(D)-R(D*).
His comments are given below.