InterLeptons News & Co

We welcome the latest results on flavor anomalies

This is an evolving post, as winter conferences are ongoing and new results are presented every day! Recently, the LHCb Collaboration has presented a new work at Moriond EW and at a public, remote, CERN seminar on the same day. They have shown the result of an update of their study of R(K). This quantity provides information on how often a B meson decays to a kaon and a pair of muons with respect to decaying to a kaon and a pair of electrons. In the standard model, R(K) is predicted to a high level of accuracy to be consistent with 1. The result of LHCb confirms a previously observed trend and shows a discrepancy at the level of 3.1 sigma with the SM prediction, providing an indication of the breaking of lepton flavor universality. We congratulate the LHCb Collaboration for such an exciting result. InterLeptons builds on the idea of lepton flavor universality violation. Therefore, we are very happy to see that more and more channels indicate a possible hint of such a phenomenon. If all the trends are confirmed, either we will observe effects also within InterLeptons, or we will be able to set very strong constraints on which new physics model can be causing the reported anomaly.
In the same direction, our Belle II colleagues have reported the results of another search of B meson decays but with a partially invisible final state, B+->K+nunu. Using an inclusive tag technique, we can already compete with previous measurements. It is interesting to note that the combined results for this channel also show a tiny tension with the SM prediction, although it's early to call it an anomaly. We congratulate our colleagues who led this study on this excellent result.