The pion form factor in QCD in NLO analytic perturbation theory

摘要

We describe the present status of the pion distribution amplitude, obtained in the nonperturbative approach based on QCD sum rules with nonlocal condensates (the BMS model) in conjunction with NLO QCD analysis of the CLEO data on F-gamma gamma*pi(Q(2)). A major task is to obtain QCD predictions for the pion electromagnetic form factor on the basis of the BMS-type pion distribution amplitude (DA), in order to compare them with the corresponding J-Lab F(pi) data. We describe all of the elements needed to perform this calculation: the NLO evolution of the pion DA; analytization and the mu(R)(2)-dependence of the pion form factor in perturbative QCD; and the matching soft and hard parts of the pion form factor. We finish with a phenomenological analysis of the obtained results.