PQCD analysis of inclusive semileptonic decays of B mesons

Sep, 1995
22 pages
Published in:
  • Phys.Rev.D 53 (1996) 4970-4981
e-Print:
Report number:
  • CCUTH-95-04,
  • IP-ASTP-14-95

Citations per year

1995200220092016202301234567
Abstract: (arXiv)
We develop the perturbative QCD formalism for inclusive semileptonic BB meson decays, which includes Sudakov suppression from the resummation of large radiative corrections near the high end of charged lepton energy. Transverse degrees of freedom of partons are introduced to facilitate the factorization of BB meson decays. Ambiguities appearing in the quark-level analysis are then avoided. A universal distribution function, arising from the nonperturbative Fermi motion of the bb quark, is constructed according to the heavy quark effective field theory based operator product expansion, through which the mean and the width of the distribution function are related to hadronic matrix elements of local operators. Charged lepton spectra of the BXuνB\to X_u\ell\nu decay are presented. We find 50\% suppression near the end point of the spectrum. The overall suppression on the total decay rate is 8\% for the free quark model, and is less than 7\% for the use of smooth distribution functions. With our predictions, it is then possible to extract the Cabibbo-Kobayashi-Maskawa matrix element Vub|V_{ub}| from experimental data. We also discuss possible implications of our analysis when confronted with the rather small observed semileptonic branching ratio in BB meson decays.
Note:
  • Section 4 on constructing the universal soft function was revised
  • 13.20.He
  • 13.25.Hw
  • 12.38.Cy
  • B: semileptonic decay
  • semileptonic decay: B
  • decay: inclusive reaction
  • inclusive reaction: decay
  • B: branching ratio
  • quantum chromodynamics: perturbation theory
  • radiative correction