Constraints on exclusive branching fractions Bi(B+→Xcil+ν) from moment measurements in inclusive B→Xclν decays

As an alternative to direct measurements, we extract the branching fractions B i ( B + → X c i l + ν ) 1 with X c i = D , D ∗ , D 0 , D 1 ′ , D 1 , D 2 , D ′ , D ′ ∗ and non-resonant final states ( D ( ∗ ) π ) n r , from a fit to electron energy, hadronic mass and combined hadronic mass–energy moments measured in inclusive B → X c l ν decays. The fit is performed by constraining the sum of exclusive branching fractions to the measured B ( B + → X c l + ν ) value, and with different sets of additional constraints for the directly measured branching fractions. There is no fit scenario in which a single branching fraction can close the gap between B ( B + → X c l + ν ) and the sum of known branching fractions B i ( B + → X c i l + ν ) . The fitted B ( B + → D ¯ ∗ 0 l + ν ) is found to be significantly larger than its direct measurement. B ( B + → D ¯ 0 l + ν ) is in good agreement with the direct measurement; when B ( B + → D ¯ ∗ 0 l + ν ) is constrained the fitted B ( B + → D ¯ 0 l + ν ) increases. Within large uncertainties, B ( B + → D ¯ 1 ′ 0 l + ν ) agrees with direct measurements. Depending on the fit scenario, B ( B + → D ¯ 0 0 l + ν ) is consistent with or larger than its direct measurement. The fit is not able to easily disentangle B + → D ¯ 1 0 l + ν and B + → D ¯ 2 0 l + ν , and tends to increase the sum of these two branching fractions. B ( B + → ( D ( ∗ ) π ) n r l + ν ) with non-resonant ( D ( ∗ ) π ) n r final states is found to be of the order 0.3 % . No indication is found for significant contributions from so far unmeasured B + → D ¯ ′ ( ∗ ) 0 l + ν decays.