Impact on L-observables of a new combined analysis of Bd,s → K(∗) form factors

Abstract

We explore the impact of a combined analysis of B_d,s → K^(∗) form factors on a set of L-observables. The L-observables are constructed from ratios of branching fractions in B_s → VV, PP, PV versus B_d → VV, PP, PV decays with P = K⁰, \( {\overline{K}}^0 \) and V = K^∗0, \( {\overline{K}}^{\ast 0} \), thereby partially reducing their hadronic uncertainties. We show the change of the Standard Model predictions of the L-observables under different determinations of the ratio of the relevant form factors (with correlations) including lattice QCD data and a novel light-cone sum rule analysis. In addition, we provide precise results for all B_d,s → K^(∗) form factors in machine-readable files. We find that the inclusion of our up-to-date results, as well as the use or omission of lattice QCD data for the form factors, has a significant impact on the L-observables. We also discuss how the New Physics interpretation is affected by the updated form factors and present revised predictions for the mechanism identified in our analysis of B → VP decays, now employing more suitable new experimental observables defined in this paper.