News from LHCb
"CERN's LHCb experiment has just announced new results which, if confirmed, would suggest hints of something beyond the Standard Model of particle physics"
Today CERN's LHCb experiment announced at the Moriond Conference and at a seminar held online at CERN new results which, if confirmed, could not be explained within the Standard Model of particle physics. The measurement compares two types of rare decays of b quarks: the first involving an electron and the second a muon (a particle similar to the electron but about 200 times heavier; we say they are both leptons, but have different flavours). The Standard Model of particle physics predicts that decays involving different flavours of leptons, should occur with the same probability (lepton flavour universality). The new result may hint a deviation from universality.
For the moment,the statistical significance of the result is 3.1 standard deviations, which implies a probability of around 0.1% that the data is compatible with the Standard Model predictions. More studies on related processes are under way. The deviation presented today is consistent with a pattern of anomalies measured in similar processes by LHCb and other experiments worldwide over the past decade. The new results are more precise than previous ones and use all the data collected by the LHCb detector so far for the first time. The LHC is expected to start running again next year following an upgrade to the accelerator and experiments.
At LIP, we are actively involved in achieving a clarification of this tantalising pattern of deviations that its referred to as flavour anomalies. We are specifically exploring the same b->sll transitions that lie at the core of the anomalies. Furthermore, we have also been exploring lepton flavour universality in top quark decays to electrons, muons and taus (published in JHEP 02(2020)191 and the subject of a recently discussed PhD thesis). We are pursuing this by analysing the LHC data already collected with the CMS experiment, as well as in the preparation for the upcoming LHC running period.