Speaker
Description
Deviations from the Standard Model have long been observed in semileptonic B-meson decays, notably $b→ s \ell \ell$ transitions, triggering speculations on potential New Physics effects in this sector. Following recent updates of $R_{K^{(*)}}$ and $BR(B_{(s)} → μμ)$, and the first measurement of $R_\phi$ by the LHCb collaboration, the sole remaining significant deviations from the SM in flavour-changing neutral currents B-decays now lie in the branching ratios of decays involving b → sμμ and in the angular observable P’5.
However, unlike $R_{K^{(*)}}$, $R_\phi$, and $BR(B_{(s)} → μμ)$, predicting $BR(B_{s}→Mμμ)$ (with $M=K^{(∗)},ϕ,…$) is challenging due to significant non-perturbative QCD effects, which introduce up to 30% theoretical uncertainty—often comparable to experimental errors— hampering the potential of these observables for discovery
We undertake a new calculation of local $B→K$ form factors using Light-Cone Sum Rules, proposing an alternative method and reassessing the systematic error associated to semi-global quark-hadron duality. These form factor predictions are then used to compute relevant observables and perform fits of NP scenarios.
