Published in:
Physical Review D 67,7 (2003) 072001;
Link to original published article:
http://dx.doi.org/10.1103/PhysRevD.67.072001
Abstract
We measure the primary lepton momentum spectrum in (B) over bar -->Xl (ν) over bar decays, for plgreater than or equal to1.5 GeV/c in the B rest frame. From this, we calculate various moments of the spectrum. In particular, we find R(0)equivalent tointegral(1.7 GeV)(dGamma/dE(sl))dEl/integral(1.5 GeV)(dGamma/dE(sl))dEl=0.6187+/-0.0014(stat)+/-0.0016(sys) and R(1)equivalent tointegral(1.5 GeV)El(dGamma/dE(sl))dEl/integral(1.5 GeV)(dGamma/dE(sl))dEl=(1.7810+/-0.0007(stat)+/-0.0009(sys)) GeV. We use these moments to determine non-perturbative parameters governing the semileptonic width. In particular, we extract the heavy quark expansion parameters (&ULambda;) over bar=(0.39+/-0.03(stat)+/-0.06(sys)+/-0.12(th)) GeV and lambda(1)=(-0.25+/-0.02(stat)+/-0.05(sys)+/-0.14(th)) GeV2. The theoretical constraints used are evaluated through order 1/M-B(3) in the non-perturbative expansion and beta(0)alpha(s)(2) in the perturbative expansion. We use these parameters to extract \V-cb\ from the world average of the semileptonic width and find \V-cb\=(40.8+/-0.5(Gammasl)+/-0.4((lambda1),((&ULambda;) over bar )exp)+/-0.9(th))x10(-3). In addition, we extract the short range b-quark mass m(b)(1S)=(4.82+/-0.07(exp)+/-0.11(th)) GeV/c(2). Finally, we discuss the implications of our measurements for the theoretical understanding of inclusive semileptonic processes.
Keywords
radiative-corrections;; semileptonic-b;; qcd;; spectrum;; mass;; physics
Date of this Version
January 2003