2023/08/08 by C. S. Bolognani, Bolognani, Carolina, Danny van Dyk +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2308.04347
openalex publication_date 2023/08/08 · openalex created_date 2023/08/18 · openalex updated_date 2026/07/28
We update the full set of Bs→ K form factors using light-cone sum rules with an on-shell kaon. Our approach determines the relevant sum rule parameters -- the duality thresholds -- from a Bayesian fit for the first time. Using a modified version of the Boyd-Grinstein-Lebed parametrisation, we combine our sum rule results at low momentum transfer q2 with more precise lattice QCD results at large q2. We obtain a consistent description of the form factors in the full q2 range. Applying these results to a recent LHCb measurement of branching ratios for the decays Bs0 → \lbrace K-, Ds-\rbrace μ+νμ, we determine the ratio of Cabibbo-Kobayashi-Maskawa elements |\fracVubVcb|_q2lt;7 \textrmGeV2 = 0.0681± 0.0040 and |\fracVubVcb|_q2gt;7 \textrmGeV2 = 0.0801± 0.0047 , which are mutually compatible at the 1.9σ level. We further comment on the sensitivity to Beyond the Standard Model effects through measurements of the shape of Bs0 → K- μ+νμ decays, in light of recent limits on such effects from other exclusive b→ uℓν processes.