Speaker
Description
Lepton Flavour Universality (LFU) is one of the fundamental properties of the Standard Model: photon, W and Z bosons are predicted to be equally coupled to the three lepton generations. Hints for possible deviations from LFU have been found by the LHCb collaboration in $b\to s \ell \ell$ and $b\to c\ell\nu$ decays, sparking great interest.This poster explains the strategy adopted to study $b\to s\ell\ell$ decays, concentrating on the experimental challenge of estimating the efficiencies. This is a key ingredient to evaluate the ratio between $B\to X \ell \ell$ branching fractions (where $X$ indicate a generic system containing a strange meson and $\ell =e,\mu$), a clean experimental observable sensitive to presence of LFU-breaking new particles.
