New results on theoretically clean observables in rare B-meson decays from LHCb

by Matteo Rama (PI)

Wednesday 7 Apr 2021, 14:00 → 16:00 Europe/Rome

Over the past decade, measurements involving the flavour changing neutral current transition b->s l+l- (l=e,mu) have shown a pattern of tensions with the Standard Model (SM) predictions. Measurements of theoretically clean observables in processes that are suppressed in the SM are powerful probes for the existence of new interactions that could alter their values. In this seminar we present new results on two key measurements, the branching fraction and lifetime of B(s)->mumu decays and the test of lepton universality with B+->K+ l+l- decays, using the complete dataset collected by the LHCb experiment. Evidence of the breaking of lepton universality with a statistical significance of 3.1 standard deviations is found. Perspectives of the measurements in the upgrade phase starting next year and in the proposed upgrade-II phase are discussed.

LFU_B2mumu_LhCb.pdf