A Study of the Fully Differential Inclusive Semileptonic B Meson Decay Rate

Citation

Lipeles, Elliot (2004) A Study of the Fully Differential Inclusive Semileptonic B Meson Decay Rate. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/W3Q5-5B34. https://resolver.caltech.edu/CaltechETD:etd-05102004-100412

Abstract

We present a study of the fully differential inclusive semileptonic B meson decay rate. Using a maximum likelihood fit, we extract the fractional contributions from the B → X_clv processes with X_c = D, D*, D**, and nonresonant X_c, and the process B → X_ulv. From the fit results, we extract moments of B → X_clυ̅ differential decay rate and the partial branching fraction of the B → X_ulυ̅ decay in a restricted region of phase space. The region in which the B → X_ulυ̅ partial branching fraction is measured is M_x < 1:5 GeV/ c², q² > 11 GeV² / c⁴. This measurements is used to extract CKM parameter |V_ub| = (4:73±0:23±0:82±0:18±0:56±0:66) x 10^-3, where the uncertainties are due to statistics, detector systematics, B → X_clv model dependence, B → X_ulυ̅ model dependence, and theoretical uncertainties. From the 〈 M²_x - M̅²_D〉moment, the first moment of the photon energy spectrum in B → X_sγ, and the semileptonic B branching fraction, we extract the CKM parameter |V_cb| = (4:12 ± .10 ± 0.09 ± 0.16) x 10_-2, where the uncertainties are due to the measurement of the semileptonic B decay rate, the moments measurements, and theoretical uncertainties. Both CKM parameter extractions use Heavy Quark Eective Theory (HQET) predictions for inclusive semileptonic B decay. The measured moments are also used to test related predictions.

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