QCD-based interpretation of the lepton spectrum in inclusiveB¯→Xuℓν¯decays

1993/11/21 by Matthias Neubert · 15 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph

paper · pdf · doi:10.1103/physrevd.49.3392

published as Phys.Rev.D49:3392-3398,1994 · 17 pages LaTeX, 3 post- script figures available upon request, CERN-TH.7087/93

arxiv created 1993/11/21 · openalex publication_date 1994/04/01 · arxiv updated 2010/11/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We present a QCD-based approach to the end-point region of the lepton spectrum in B\ensuremath→X_u\ensuremathℓ\ensuremathν decays. A genuinely nonperturbative form factor, the shape function, describes the falloff of the spectrum close to the end point. The moments of this function are related to forward scattering matrix elements of local, higher-dimension operators. We find that nonperturbative effects are dominant over a finite region in the lepton energy spectrum, the width of which is related to the kinetic energy of the b quark inside the B meson. In this region, a resummation of the most singular terms in the operator product expansion is performed. Applications of our method to the extraction of fundamental standard model parameters, among them V_ub, are discussed.

Citations

• Inclusive semileptonicBand polarizedΛbdecays from QCD

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• Note on the extraction of |Vub| using radiative B decays
• On the inclusive determination of Vub from the lepton invariant mass spectrum
• Two-loop relations for heavy-quark parameters in the shape-function scheme
• Shape function in QED and bound muon decays
• A new model-independent method of determining || and |V|
• Two-loop jet function and jet mass for top quarks
• Toward a NNLO calculation of the B¯→Xsγ decay rate with a cut on photon energy: I. Two-loop result for the soft function
• Towards the anomalous dimension toO(ΛQCD/mb)for phase space restrictedB¯→Xuℓν¯andB¯→Xsγ
• Cancellation of renormalon ambiguities in the heavy quark effective theory
• Theory of inclusive B decays
• Enhanced subleading structure functions in semileptonic B decay