Pion structure: from nonlocal condensates to NLO analytic perturbation theory

Abstract

A pion distribution amplitude, derived from nonlocal QCD sum rules, has been employed to calculate $F_{{\gamma }^{\ast }\gamma \to \pi }(Q^2)$ using light-cone sum rules, and $F_{\pi }(Q^2)$ in NLO QCD perturbation theory. Predictions are presented for both observables and found to be in good agreement with the corresponding data. Calculating the hard pion form factor by Analytic Perturbation Theory to two-loop order, it is shown that the renormalization-scheme and scale-setting dependencies are diminished.

9 pages, 4 figures consisting of 6 eps files. Needs hsqcd.cls. Invited plenary talk presented by the first author at Hadron Structure and QCD: from Low to High Energies, St. Petersburg, Repino, Russia, 18-22 May 2004