Semileptonic Inclusive B--Decays and the Determination of $|V_{ub}|$ from QCD Sum Rules

Abstract

We calculate the electron spectrum of semileptonic decays of B-mesons into non-charmed hadrons. The shape of the spectrum obtained from QCD sum rules is in general agreement with quark model calculations. At high electron energies the decrease of the spectrum is less steep than predicted by Altarelli et al. Our analysis yields a total decay rate $\Gamma (B\to X_{u}e\bar{\nu })=(6.8\pm 2.0)10^{13}|V_{ub}{|}^2{s}^{-1}$. For the spectrum integrated over electron energies in the interval $2.4{ GeV}\leq E_e \leq 2.6\mbox{\ GeV}$ in the laboratory frame we obtain $\Gamma (B\to X_{u}e\bar{\nu })=(5.0\pm 1.6)10^{12}|V_{ub}{|}^2{s}^{-1}$. Estimating all sorts of theoretical uncertainties, we obtain $|V_{ub}|=0.003\pm 0.001$ for the $b\to u$ weak transition matrix element from the new CLEO-data.

21 pages + 6 postscript figures, appended as uuencoded file, uses REVTEX, HD-THEP-92-35

References in corpus (2)

• Nonperturbative Corrections to Inclusive Beauty and Charm Decays: QCD versus Phenomenological Models
• The Isgur-Wise Function to $O({\alpha }_s)$ from Sum Rules in the Heavy Quark Effective Theory

Cited by in corpus (10)

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• $B \rar K^* \ γ$} from Hybrid Sum Rule
• Gold-plated Mode of CP-Violation in Decays of B_c Meson from QCD Sum Rules
• QCD sum rules with spectral densities solved in inverse problems
• A new method of determining $|V_{ub}|$ by the processes $\bar{B}\to \rho l\bar{\nu }$ and $\bar{B} \to K^* l \lbar$
• Distribution of valence quarks and light-cone QCD sum rules
• $V_{ub}$ from the Hadron Energy Spectrum in Inclusive Semileptonic B Decays
• Twist-2 Light-Cone Pion Wave Function