A connection between inclusive semileptonic decays of bound and free heavy quarks

Abstract

A relativistic constituent quark model, formulated on the light-front, is used to derive a new parton approximation for the inclusive semileptonic decay width of the B-meson. A simple connection between the decay rate of a free heavy-quark and the one of a heavy-quark bound in a meson or in a baryon is established. The main features of the new approach are the treatment of the b-quark as an on-mass-shell particle and the inclusion of the effects arising from the b-quark transverse motion in the B-meson. In a way conceptually similar to the deep-inelastic scattering case, the B-meson inclusive width is expressed as the integral of the free b-quark partial width multiplied by a bound-state factor related to the b-quark distribution function in the B-meson. The non-perturbative meson structure is described through various quark-model wave functions, constructed via the Hamiltonian light-front formalism using as input both relativized and non-relativistic potential models. A link between spectroscopic quark models and the B-meson decay physics is obtained in this way. Our predictions for the B -> X_c l nu_l and B -> X_u l nu_l decays are used to extract the CKM parameters |V_cb| and |V_ub| from available inclusive data. After averaging over the various quark models adopted and including leading-order perturbative QCD corrections, we obtain |V_cb| = (43.0 +/- 0.7_exp +/- 1.8_th) 10^-3 and |V_ub| = (3.83 +/- 0.48_exp +/- 0.14_th) 10^-3, implying |V_ub / V_cb| = 0.089 +/- 0.011_exp +/- 0.005_th, in nice agreement with existing predictions.

arXiv commentrevised version with pQCD corrections included, to appear in Physical Review D

References in corpus (30)

• QCD Predictions for Lepton Spectra in Inclusive Heavy Flavour Decays
• Semileptonic Meson Decays in the Quark Model: An Update
• Inclusive Semileptonic B and Polarized Lambda_b Decays from QCD
• Differential Distributions in Semileptonic Decays of the Heavy Flavors in QCD
• On the Motion of Heavy Quarks inside Hadrons: Universal Distributions and Inclusive Decays
• Aspects Of Heavy Quark Theory
• Analysis of the Photon Spectrum in Inclusive $B\to X_s\gamma$ Decays
• Operator Product Expansion for Inclusive Semileptonic Decays in Heavy Quark Effective Field Theory
• Semileptonic B decays to excited charmed mesons
• Electromagnetic form factors of the $\rho$ meson in a light-front constituent quark model
• B Decays and CP Violation
• Resummation of Nonperturbative Corrections to the Lepton Spectrum in Inclusive $B\to X\ell \bar{\nu }$ Decays
• Hard Constituent Quarks and Electroweak Properties of Pseudoscalar Mesons
• Charge form factor of $\pi$ and $K$ mesons
• V_{ub} from the Hadronic Invariant Mass Spectrum in Semileptonic B Decay
• Nonleptonic Decays and Lifetimes of b-quark and c-quark Hadrons
• Model independent results for $B\to D_1(2420)\ell \bar{\nu }$ and $B\to D_2^{\ast }(2460)\ell \bar{\nu }$ at order ${\Lambda }_{QCD}/m_{c,b}$
• Heavy Quark Distribution Function in QCD and the AC${}^2$M${}^2$ Model
• Weak Decay Form Factors of Heavy Pseudoscalar Mesons within a Light-Front Constituent Quark Model
• Radiative $\pi \rho$ and $\pi \omega$ transition form factors in a light-front constituent quark model
• b -> s +γ: A QCD Consistent Analysis of the Photon Energy Distribution
• A Parton Model for Inclusive Semileptonic B Meson Decays
• Calculation of the Isgur-Wise function from a light-front constituent quark model
• Semi-leptonic B decays into higher charmed resonances
• Exclusive and inclusive weak decays of the B-meson
• The ACCMM Model and the Heavy Quark Expansion
• $1/m_b$ Corrections in the ACCMM Model for Inclusive Semileptonic B Decay
• Heavy-quark binding and kinetic energies in heavy-light mesons and the constituent quark model
• Theoretical Aspects of the Heavy Quark Expansion
• Charmed decays of the B-meson in the quark model

Cited by in corpus (5)

• The lifetime of B_c-meson and some relevant problems
• Quark-binding effects in inclusive decays of heavy mesons
• The bound state corrections to the semileptonic decays of the B meson. The light-front approach versus ACM model
• Selected Theoretical Issues in B-meson Physics: CKM matrix and Semileptonic Decays
• The Lambda_b lifetime in the light front quark model