b → sl+l- global fits after RKS and RK*+

We present an up-to-date complete model-inde- pendent global fit to b -> sll observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of R-K, R-KS, R-K*+, B-S -> phi mu(+)mu(-) and B-s -> mu(+)mu(-) 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 C-9'mu and C-10'mu, remains a viable possibility. Second, a lepton flavour universality violating (LFUV) left-handed lepton coupling (C-9 mu(V) = C-10 mu(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 C-9(U). We observe that the LFUV observable Q(5) offers a very interesting possibility to separate both types of scenarios.

Automated summary

We present an up-to-date complete model-independent global fit to b -> sll observables and confirm patterns of New Physics able to explain the data. The results suggest that both right-handed couplings and lepton flavour universality violating (LFUV) left-handed lepton couplings are possibilities, and the LFUV observable Q(5) can distinguish between these two scenarios.