Subleading Shape Functions in Inclusive B Decays
نویسندگان
چکیده
The contributions of subleading shape functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft-collinear and heavy-quark effective theory. At tree-level, the results can be expressed in terms of forward matrix elements of bi-local light-cone operators. Fourquark operators, which arise at O(αs), are included. Our results are in disagreement with some previous studies of subleading shape-function effects. A numerical analysis of B̄ → Xu lν̄ decay distributions suggests that power corrections are small, with the possible exception of the endpoint region of the charged-lepton energy spectrum.
منابع مشابه
Subleading Jet Functions in Inclusive B Decays
The contribution of subleading jet functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft collinear and heavy quark effective theory. Focusing on the tree level matching of QCD onto soft collinear effective theory, the subleading jet functions are defined to all orders in αs(μi) (with μ 2 i ∼ mbΛQCD) and are ca...
متن کاملLight - cone distribution functions for B decays at subleading order in 1 / m b
We construct the higher twist structure functions that describe inclusive b hadron decays in regions of phase space where the hadronic decay products carry high energy but have low invariant mass. We show that, for B meson decays, there are four new non-vanishing matrix elements of non-local operators. We show that to subleading twist these decays are parametrized in terms of four functions. We...
متن کاملLight-cone distribution functions for B decays at subleading order in 1Õmb
We construct the higher twist structure functions that describe inclusive b hadron decays in regions of phase space where the hadronic decay products carry high energy but have low invariant mass. We show that, for B meson decays, there are four new nonvanishing matrix elements of nonlocal operators. We show that to subleading twist these decays are parametrized in terms of four functions. We c...
متن کاملReparametrization Invariance in Inclusive Decays of Heavy Hadrons
Reparametrization invariance is the invariance of the heavy mass limit under small changes of the heavy-quark four velocity. We discuss the implications of this invariance for non-local light cone operators, the matrix elements of which are relevant for the leading and subleading shape functions describing differential rates for inclusive heavy-to-light transitions.
متن کاملImpact of Four-Quark Shape Functions on Inclusive B Decay Spectra
It has recently been pointed out that a new class of subleading shape functions involving B-meson matrix elements of non-local four-quark operators contributes at order ΛQCD/mb to B̄ → Xu l ν̄ decay distributions in the endpoint region. The corresponding functions fu(ω) and fv(ω) are estimated using the vacuum-insertion approximation. A numerical analysis of various B̄ → Xu l ν̄ decay spectra sugge...
متن کامل