Three-Scale Factorization Theorem and Effective Field Theory
نویسندگان
چکیده
We develop a perturbative QCD factorization theorem which is compatible with effective field theory. The factorization involves three scales: an infrared cutoff of order ΛQCD, a hard scale of order the B meson mass, and an ultraviolet cutoff of order the W boson mass. Our approach is renormalization group invariant and moderates the scale-dependence problem in effective field theory. Applying this formalism to exclusive nonleptonic B meson decays, we clarify the controversy over the Bauer-Stech-Wirbel parameters a2/a1 for charm and bottom decays. It is found that the nonfactorizable contribution plays an important role in the explanation of the sign and magnitude of a2/a1.
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