Abstract
We obtain new estimates for the parameters $\lambda_{E}^2$, $\lambda_H^2$ and their ratio $\mathcal{R} = \lambda_{E}^2/\lambda_H^2$, which appear in the second moments of the $B$-meson light-cone distribution amplitudes defined in the heavy-quark effective field theory. The computation is based on two-point QCD sum rules for the diagonal correlation function and includes all contributions up to mass dimension seven in the operator-product expansion. For the ratio we get $\mathcal{R} = (0.1 \pm 0.1)$ with $\lambda_H^2 = (0.15 \pm 0.05) \, \text{GeV}^2$ and $\lambda_E^2 = (0.01 \pm 0.01) \, \text{GeV}^2$.
Highlights
Light-cone distribution amplitudes (LCDAs) are of great importance in exclusive B-meson decays like B → ππ or B → πK in the heavy quark limit and allow for the study of CP-violation in weak interactions
LCDAs appear in factorization theorems such as QCD factorization [2,4,5], since these amplitudes encode the nonperturbative nature of the strong interactions and are crucial in B-meson decay form factor computations
Contrary to light-meson distribution amplitudes, which appear in factorization theorems, the properties of the B-meson distribution amplitudes are less known
Summary
Light-cone distribution amplitudes (LCDAs) are of great importance in exclusive B-meson decays like B → ππ or B → πK in the heavy quark limit and allow for the study of CP-violation in weak interactions. In the case of local quark operators, these matrix elements can be expressed in terms of the parameters λ2E;H, which contribute to the second Mellin moments of the three-particle B-meson distribution amplitudes. These are the parameters of particular interest in this work. These authors argued in their work that a consistent treatment of all OðαsÞ contributions should resolve the stability problem, which is related to the fact that the OPE does not converge for the parameters λ2E;H in [3] For this analysis, they included the OðαsÞ corrections of the coupling constant FðμÞ as well, which, albeit leading to good convergence of the OPE, obey large higher order perturbative corrections [27,28].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
