Constraints on exclusive branching fractions $BF_i(B^+\to X_c^il^+\nu)$ from moment measurements in inclusive $B\to X_cl\nu$ decays

Understand

As an alternative to direct measurements, we extract exclusive branching fractions of semileptonic B-meson decays to charmed mesons, $BF_i(B\to X_c^il\nu)$ with $X_c^i = D, D^*, D_0, D'_1, D_1, D_2, D', D'^*$ and non-resonant final states $(D^{(*)}\pi)_{nr}$, from a fit to electron energy, hadronic mass and combined hadronic mass-energy moments measured in inclusive $B\to X_cl\nu$ decays.

• The fit is performed by constraining the sum of exclusive branching fractions to the measured value of $BF(B\to X_cl\nu)$, and with different sets of additional constraining terms for the directly measured branching fractions.
• There is no fit scenario in which a single branching fraction alone is enhanced to close the gap between $BF(B\to X_cl\nu)$ and the sum of known branching fractions $BF_i(B\to X_c^il\nu)$.
• The fitted $BF(B\to D^*l\nu)$ is 5% to 10% larger than the direct measurement depending on whether or not $BF(B\to D^*l\nu)$ is constrained to its direct measurement.