Thursday, February 26, 2025, 16:00
on zoom
David London, Université de Montréal
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.