A study of the fully differential inclusive semileptonic B meson decay rate

B meson;hadronic mass moments;HQET;semileptonic;Vcb;Vub

Lipeles, Elliot ; Weinstein, Alan Jay

University:California Institute of Technology

Department:Physics, Mathematics and Astronomy

关键词: B meson;    hadronic mass moments;    HQET;    semileptonic;    Vcb;    Vub;   

Others  :  https://thesis.library.caltech.edu/1714/1/thesis.pdf

美国|英语

来源: Caltech THESIS

【 摘 要 】

We present a study of the fully differential inclusive semileptonic B meson decay rate. Using amaximum likelihood t, we extract the fractional contributions from the B -> Xclv processes withXc = D, D*, D**, and nonresonant Xc, and the process B -> Xulv. From the fit results, we extractmoments of B -> Xclv differential decay rate and the partial branching fraction of the B -> Xulvdecay in a restricted region of phase space. The region in which the B -> Xulv partial branchingfraction is measured is MX < 1:5 GeV/ c2, q2 >11 GeV2 / c4. This measurements is used to extractCKM parameter |Vub| = (4:73+-0:23+-0:82+-0:18+-0:56+-0:66) x 10(^-3), where the uncertainties aredue to statistics, detector systematics, B -> Xclv model dependence, B -> Xulv model dependence,and theoretical uncertainties. From the moment, the first moment of the photon energyspectrum in B -> Xs lambda, and the semileptonic B branching fraction, we extract the CKM parameter|Vcb| = (4:12 +- .10 +- 0.09 +- 0.16) x 10(^-2), where the uncertainties are due to the measurement ofthe semileptonic B decay rate, the moments measurements, and theoretical uncertainties. BothCKM parameter extractions use Heavy Quark Eective Theory (HQET) predictions for inclusivesemileptonic B decay. The measured moments are also used to test related predictions.