QCD Factors a 1 and a 2 Beyond Leading Logarithms versus Factorization in Non - leptonic Heavy Meson Decays ∗
نویسنده
چکیده
We calculate the QCD factors a1 and a2, entering the tests of factorization in nonleptonic heavy meson decays, beyond the leading logarithmic approximation in three renormalization schemes (NDR, HV, DRED). We investigate their μ–dependence and the renormalization scheme dependence. We point out that a1 for B-decays depends very weakly on ΛMS, μ and the choice of the renormalization scheme. For Λ (5) MS = 225±85MeV and 4 GeV ≤ μ ≤ 8 GeV we find a1 = 1.01±0.02 in accordance with phenomenology. The ΛMS, μ and scheme dependences of a2 are on the other hand sizable. Interestingly, for the NDR scheme we find a 2 = 0.20± 0.05, in the ball park of recent phenomenological results and substantially larger than leading order estimates. However a 2 = 0.16± 0.05 and a 2 = 0.15± 0.05. Implications of these findings for the tests of factorization in B-decays and D-decays are critically discussed. ∗Supported by the German Bundesministerium für Forschung und Technologie under contract 06 TM 732 and by the CEC science project SC1–CT91–0729.
منابع مشابه
QCD factorization for exclusive non - leptonic B - meson decays : General arguments and the case of heavy – light final states
QCD factorization for exclusive non-leptonic B-meson decays: General arguments and the case of heavy–light final states Abstract We provide a rigorous basis for factorization for a large class of non-leptonic two-body B-meson decays in the heavy-quark limit. The resulting factorization formula incorporates elements of the naive factorization approach and the hard-scattering approach , but allow...
متن کاملB?J/?(?,K) Decays within QCD Factorization Approach
We used QCD factorization for the hadronic matrix elements to show that the existing data, in particular the branching ratios BR ( ?J/?K) and BR ( ?J/??), can be accounted for this approach. We analyzed the decay within the framework of QCD factorization. We have complete calculation of the relevant hard-scattering kernels for twist-2 and twist-3. We calculated this decays in a special scale ...
متن کاملThe Radiative Decays B → V γ at Next-to-Leading Order in QCD
We provide a model-independent framework for the analysis of the radiative B-meson decays B → Kγ and B → ργ. In particular, we give a systematic discussion of the various contributions to these exclusive processes based on the heavy-quark limit of QCD. We propose a novel factorization formula for the consistent treatment of B → V γ matrix elements involving charm (or up-quark) loops, which cont...
متن کاملA Quark-Meson Model for Heavy Mesons: Semi-Leptonic Decays
I consider a model for heavy meson decays based on an effective quark-meson Lagrangian. The model is constrained by the known symmetries of QCD in the mQ → ∞ limit for the heavy quarks, and chiral symmetry in the light quark sector. Using a limited number of free parameters it is possible to compute several phenomenological quantities, e.g. the leptonic B and B∗∗ decay constants; the Isgur-Wise...
متن کاملar X iv : h ep - p h / 02 11 38 1 v 1 2 5 N ov 2 00 2 1 Radiative corrections to radiative B decays : Exclusive B → V γ at NLO
We discuss a model-independent framework for the analysis of the radiative B-meson decays B → K * γ and B → ργ based on the heavy-quark limit of QCD. We present a factorization formula for the treatment of B → V γ matrix elements involving charm (or up-quark) loops, which contribute at leading power in ΛQCD/mB to the decay amplitude. Annihilation topologies are power suppressed, but still calcu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1994