First extraction of inclusive Vcb from q2 moments

We present the first determination of Vcb from inclusive B→ Xcℓ 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/mb4 purely from data and can potentially reduce the uncertainty on Vcb. In this paper, we present our first determination of Vcb using this method. Combining the recent measurements of q2 moments by Belle and Belle II, our default fit gives |Vcb| = (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.