V{sub ub} from the hadron energy spectrum in inclusive semileptonic B decays

Journal Article · Wed Oct 01 04:00:00 EDT 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.56.4250· OSTI ID:542770

Greub, C ^[1]; Rey, S ^[2]

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1. Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States)
2. Stanford Linear Accelerator Center and Department of Physics, Stanford University, Stanford, California 94309 (United States)

A measurement of the hadron energy spectrum in inclusive semileptonic B decays is proposed as a viable method for extracting {vert_bar}V{sub ub}{vert_bar}. Compared to the traditional energy spectrum of the charged lepton, the hadron energy spectrum exhibits kinematical advantages such as a wider energy window and a larger signal branching fraction. The hadron energy distribution is calculated in the approach of the model of Altarelli {ital et al.} and of the heavy-quark effective field theory. In both methods, perturbative QCD corrections, the Fermi motion of the b quark in the B meson, and the recoil momentum of the B meson [stemming from the {Upsilon}(4S) resonance] are taken into account. We find excellent agreement between the spectra calculated in both methods, especially in the relevant kinematical region below the charmed meson threshold. The theoretical error to {vert_bar}V{sub ub}{vert_bar}, which is dominated by the uncertainty of the b-quark mass, is estimated to be at the {plus_minus}12{percent} level. Experimental techniques utilized in the recent measurement of exclusive semileptonic b{r_arrow}u decays point to the feasibility of the present proposal both at CLEO and at future B factories. {copyright} {ital 1997} {ital The American Physical Society}

• Research Organization: Stanford Linear Accelerator Center
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 542770
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 7 Vol. 56; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
B MESONS
B QUARKS
BRANCHING RATIO
ENERGY SPECTRA
HADRONS
INCLUSIVE INTERACTIONS
KOBAYASHI-MASKAWA MATRIX
MATRIX ELEMENTS
PERTURBATION THEORY
QUANTUM CHROMODYNAMICS
SEMILEPTONIC DECAY