Perturbative Effects in the Form Factor \gamma\gamma^*\to \pi and Extraction of the Pion Wave Function from CLEO Data
High Energy Physics - Phenomenology
2016-09-06 v2
Abstract
We study the pion form factor F^{\pi \gamma\gamma^*}(Q^2) in the light-cone sum rule approach, accounting for radiative corrections and higher twist effects. Comparing the results to the CLEO experimental data on F^{\pi \gamma\gamma^*}(Q^2), we extract the the pion distribution amplitude of twist-2. The deviation of the distribution amplitude from the asymptotic one is small and is estimated to be a_2(\mu) = 0.12 \pm 0.03 at \mu=2.4 GeV, in the model with one non-asymptotic term. The ansatz with two non-asymptotic terms gives some region of a_2 and a_4, which is consistent with the asymptotic distribution amplitude, but does not agree with some old models.
Keywords
Cite
@article{arxiv.hep-ph/9905392,
title = {Perturbative Effects in the Form Factor \gamma\gamma^*\to \pi and Extraction of the Pion Wave Function from CLEO Data},
author = {Alexander Schmedding and Oleg Yakovlev},
journal= {arXiv preprint arXiv:hep-ph/9905392},
year = {2016}
}
Comments
21 pages, LaTeX, 7 eps figures; (v2): Phys. Rev. D version