HADRONIC SPECTRAL MOMENTS IN SEMILEPTONIC B-DECAY WITH A LEPTON ENERGY CUT

We compute the first two moments [(s(H)-(m) over bar(D)(2))(1,2)] of t he final hadronic invariant mass in the inclusive decay B-->X(c)l(nu)( -), in the presence of a cut E-l(min) on the charged lepton energy. Th ese moments may be measured directly by experiments at the Y(4S) using the neutrino reconstruction technique, which requires such a cut. Mea surement of these moments will place constraints on the nonperturbativ e parameters <(Lambda)over bar> and lambda(1), which are relevant for extracting the quark masses m(b) and m(c), as well as the CKM angle V- cb. We include terms of order alpha(s)(2) beta(0) and 1/m(b)(3) in the operator product expansion, and use the latter to estimate the theore tical uncertainty in the extraction of <(Lambda)over bar> and lambda(1 ). [S0556-2821(98)00701-2].