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The gluon content of the $η$ and $η^{\prime}$ mesons

N. G. Stefanis·S. S. Agaev
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Abstract

We analyze power-suppressed contributions to singlet pseudoscalar $η$ and $η^{\prime}$ meson transition form factors. These corrections stem from endpoint singularities and help improve the agreement between QCD theory and the experimental data, in particular, at low-momentum transfers. Using the CLEO data, we extract information on the profile of the $η_1$ and $η_8$ distribution amplitudes in the $SU(3)_{F}$ octet-singlet basis employing both the one-angle and the two-angle mixing schemes. In the former scheme, we find good agreement with the CLEO data, while in the second case, our approach requires non-asymptotic profiles for these mesons.

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N. G. Stefanis, S. S. Agaev. 2004-09-19. The gluon content of the $η$ and $η^{\prime}$ mesons. https://arxiv.org/abs/hep-ph/0409198

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