Study of the leptonic decays of pseudoscalarB,Dand vectorB*,D*mesons and of the semileptonicB→DandB→D*decays

2005/02/28 by C. Albertus, E. Hernández, J. Nieves +2 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th

paper · pdf · doi:10.1103/physrevd.71.113006

published as Phys.Rev. D71 (2005) 113006 · 19 Latex pages,6 figures, references added, corrected typos, content enlarged

arxiv created 2005/04/21 · openalex publication_date 2005/06/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01

Abstract

We present results for different observables in weak decays of pseudoscalar and vector mesons with a heavy c or b quark. The calculations are done in a nonrelativistic constituent quark model improved at some instances by heavy quark effective theory constraints. We determine pseudoscalar and vector meson decay constants that within a few percent satisfy f_VM_V/f_PM_P=1, a result expected in heavy quark symmetry when the heavy quark masses tend to infinity. We also analyze the semileptonic B\ensuremath→D and B\ensuremath→D^* decays for which we evaluate the different form factors. Here we impose heavy quark effective theory constraints among form factors that are not satisfied by a direct quark model calculation. The value of the form factors at zero recoil allows us to determine, by comparison with experimental data, the value of the |V_cb| Cabibbo-Kobayashi-Maskawa matrix element. From the B\ensuremath→D semileptonic decay we get |V_cb|=0.040\ifmmode±\else\textpm\fi0.006, in perfect agreement with our previous determination based on the study of the semileptonic \ensuremathΛ_b\ensuremath→\ensuremathΛ_c decay and also in excellent agreement with a recent experimental determination by the DELPHI Collaboration. We further make use of the partial conservation of axial current hypothesis to determine the strong coupling constants g_B^*B\ensuremathπ(0)=60.5\ifmmode±\else\textpm\fi1.1 and g_D^*D\ensuremathπ(0)=22.1\ifmmode±\else\textpm\fi0.4. The ratio R=(g_B^*B\ensuremathπ(0)f_B^*√M_D)/(g_D^*D\ensuremathπ(0)f_D^*√M_B)=1.105\ifmmode±\else\textpm\fi0.005 agrees with the heavy quark symmetry prediction of 1.

Citations

• Measurement of theB¯0→D*+ℓ−ν¯ℓdecay rate and|Vcb|
• coupling (gB*Bπ,gD*Dπ); A quark model with Dirac equation
• Decay constants of pseudoscalar mesons in a relativistic quark model
• Measurement of (→Dℓ) and determination of |V|
• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• B → Dlν form factors and the determination of |Vcb|
• Measurement of |V_cb| using the semileptonic decay B⁰_d → D*⁺ l^-ν_l

Cited by

• SemileptonicB→πdecays from an Omnès improved nonrelativistic constituent quark model