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


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.


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 → Xclv processes with Xc = D, D*, D**, and nonresonant Xc, and the process B → Xulv. From the fit results, we extract moments of B → Xclυ̅ differential decay rate and the partial branching fraction of the B → Xulυ̅ decay in a restricted region of phase space. The region in which the B → Xulυ̅ partial branching fraction is measured is Mx < 1:5 GeV/ c2, q2 > 11 GeV2 / c4. This measurements is used to extract CKM parameter |Vub| = (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 → Xclv model dependence, B → Xulυ̅ model dependence, and theoretical uncertainties. From the 〈 M2x - M̅2D〉moment, the first moment of the photon energy spectrum in B → X, 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 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.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:B meson; hadronic mass moments; HQET; semileptonic; Vcb; Vub
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Awards:John Stager Stemple Memorial Prize in Physics, 1999.
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Weinstein, Alan Jay
Thesis Committee:
  • Weinstein, Alan Jay (chair)
  • Filippone, Bradley W.
  • Porter, Frank C.
  • Wise, Mark B.
Defense Date:8 October 2003
Non-Caltech Author Email:lipeles (AT)
Record Number:CaltechETD:etd-05102004-100412
Persistent URL:
Lipeles, Elliot0000-0001-5982-7326
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1714
Deposited By: Imported from ETD-db
Deposited On:13 May 2004
Last Modified:21 Jan 2021 00:24

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