$$b\rightarrow s\ell ^+\ell ^-$$ global fits after $$R_{K_S}$$ and $$R_{K^{*+}}$$

Abstract

AbstractWe present an up-to-date complete model-independent global fit to $$b\rightarrow s\ell \ell $$ b → s ℓ ℓ observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of $$R_K$$ R K , $$R_{K_S}$$ R K S , $$R_{K^{*+}}$$ R K ∗ + , $$B_s \rightarrow \phi \mu ^+\mu ^-$$ B s → ϕ μ + μ - and $$B_s\rightarrow \mu ^+\mu ^-$$ B s → μ + μ - in our analysis, which now includes 254 observables. This updates our previous analyses and strengthens their two main outcomes. First, the presence of right-handed couplings encoded in the Wilson coefficients $${{\mathcal {C}}}_{9'\mu }$$ C 9 ′ μ and $${{\mathcal {C}}}_{10'\mu }$$ C 10 ′ μ remains a viable possibility. Second, a lepton flavour universality violating (LFUV) left-handed lepton coupling ($${{\mathcal {C}}}_{9\mu }^{\mathrm{V}}=-{{\mathcal {C}}}_{10\mu }^{\mathrm{V}}$$ C 9 μ V = - C 10 μ V ), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal New Physics is allowed, in particular in $${{\mathcal {C}}}_{9}^{\mathrm{U}}$$ C 9 U . We observe that the LFUV observable $$Q_5$$ Q 5 offers a very interesting possibility to separate both types of scenarios.