Speaker: Prof. David London (Universite de Montreal)
Talk title: Anomalies in Hadronic B Decays
Time: 2026/02/23 (Mon.) 12:30
Place: NCTS Physics 4F Lecture Hall, Cosmology Hall, NTU
Online: https://nationaltaiwanuniversity-zbh.my.webex.com/nationaltaiwanuniversity-zbh.my-tc/j.php?MTID=mbfbf77049752905e6fe55228dfd126e2
            Meeting Number: 2556 542 2983
            Password: mKZWcSsM899 (65992776 when dialing from a phone or video system)

Abstract: 
As the LHC has not found any new particles, we must use indirect searches to look for signs of new physics. There have been a number of claims of anomalies in certain hadronic B decays, but they are not convincing, as they generally involve theoretical input and/or have unknown QCD corrections. My collaborators and I recently performed a global fit to all B → P P decays (P is a pseudoscalar meson) under the assumption of flavour SU(3) symmetry (SU(3)F ). We find a disagreement with the SM at the level of 4.1σ. This can be accounted for by adding SU(3)F -breaking effects, but 1000% breaking is required, far larger than the ∼ 30% expected in the SM. This result is rigorous, group-theoretically – no theoretical input is involved. But if some well-motivated theoretical input is added, the discrepancy grows to 4.9σ.