Measurements of moments of the hadronic mass distribution in semileptonicBdecays

We report a measurement of the first four moments of the hadronic mass distribution in $\overline{B}\to X_c{\mathcal{l}}^{-}\overline{\nu }$ decays. The measurements are based on 89 million ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}\to B\overline{B}$ events where the hadronic decay of one of the B mesons is fully reconstructed and a charged lepton from the decay of the other B meson is identified. The moments are presented for minimum lepton momenta ranging from 0.9 to 1.6 GeV in the B rest frame. It is expected that such measurements will lead to improved determinations of $|V_{\mathrm{cb}}|$ and $|V_{\mathrm{ub}}|.$