First extraction of inclusive Vcb from q2 moments

We present the first determination of V_cb from inclusive $$ B\to {X}_c \ell {\overline{v}}_{\ell} $$B → X c ℓ v ¯ ℓ using moments of the dilepton invariant mass, q². These moments are reparametrization invariant quantities and depend on a reduced set of non-perturbative parameters. This reduced set of parameters opens a new path to extract these parameters up to $$ 1/{m}_b^4 $$1 / m b 4 purely from data and can potentially reduce the uncertainty on V_cb. In this paper, we present our first determination of V_cb using this method. Combining the recent measurements of q² moments by Belle and Belle II, our default fit gives |V_cb| = (41.69±0.63)·10⁻³. This result presents an important independent cross check of, and is consistent with, the previous state-of-the-art inclusive determinations using lepton energy and hadronic invariant mass moments.