scholarly journals Perturbative limit of the two-pion light-cone distribution amplitude

2000 ◽  
Vol 61 (7) ◽  
Author(s):  
M. Diehl ◽  
Th. Feldmann ◽  
P. Kroll ◽  
C. Vogt
2011 ◽  
Vol 26 (37) ◽  
pp. 2761-2782 ◽  
Author(s):  
ZHI-GANG WANG

In this paper, we study the [Formula: see text] form-factors with the light-cone QCD sum rules, where the B-meson light-cone distribution amplitudes are used. In calculations, we observe that the line-shapes of the B-meson light-cone distribution amplitude ϕ+(ω) have significant impacts on the values of the form-factors, and expect to obtain severe constraints on the parameters of the B-meson light-cone distribution amplitudes from the experimental data in the future.


2020 ◽  
Vol 102 (1) ◽  
Author(s):  
Wei Wang ◽  
Yu-Ming Wang ◽  
Ji Xu ◽  
Shuai Zhao

2005 ◽  
Vol 20 (32) ◽  
pp. 7451-7484 ◽  
Author(s):  
ANDREY GROZIN

B-meson light-cone distribution amplitudes are discussed in these lectures in the framework of HQET. The evolution equation for the leading-twist distribution amplitude is derived in one-loop approximation. QCD sum rules for distribution amplitudes are discussed.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Tadeusz Janowski ◽  
Ben Pullin ◽  
Roman Zwicky

Abstract We present the first analytic $$ \mathcal{O}\left({\alpha}_s\right) $$ O α s -computation at twist-1,2 of the $$ {\overline{B}}_{u,d,s} $$ B ¯ u , d , s → γ form factors within the framework of sum rules on the light-cone. These form factors describe the charged decay $$ {\overline{B}}_u\to \gamma {\mathrm{\ell}}^{-}\overline{v} $$ B ¯ u → γ ℓ − v ¯ , contribute to the flavour changing neutral currents $$ {\overline{B}}_{d,s}\to \gamma {\mathrm{\ell}}^{+}{\mathrm{\ell}}^{-} $$ B ¯ d , s → γ ℓ + ℓ − and serve as inputs to more complicated processes. We provide a fit in terms of a z-expansion with correlation matrix and extrapolate the form factors to the kinematic endpoint by using the gBB*γ couplings as a constraint. Analytic results are available in terms of multiple polylogarithms in the supplementary material. We give binned predictions for the $$ {\overline{B}}_u\to \gamma {\mathrm{\ell}}^{-}\overline{v} $$ B ¯ u → γ ℓ − v ¯ branching ratio along with the associated correlation matrix. By comparing with three SCET-computations we extract the inverse moment B-meson distribution amplitude parameter λB = 360(110) MeV. The uncertainty thereof could be improved by a more dedicated analysis. In passing, we extend the photon distribution amplitude to include quark mass corrections with a prescription for the magnetic vacuum susceptibility, χq, compatible with the twist-expansion. The values χq = 3.21(15) GeV−2 and χs = 3.79(17) GeV−2 are obtained.


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