FIZIKA B 17 (2008) 2, 217 - 230

 

PION STRUCTURE IN QCD: FROM THEORY TO LATTICE TO EXPERIMENTAL DATA

 A. P. BAKULEVa, S. V. MIKHAILOVa, A. V. PIMIKOVa and N. G. STEFANISb

aBogoliubov Lab. of Theoretical Physics, JINR, 141980 Dubna, Russia
E-mail addresses: bakulev@theor.jinr.ru, mikhs@theor.jinr.ru, pimikov@theor.jinr.ru 
bITP-II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
E-mail address: stefanis@tp2.ruhr-uni-bochum.de

Received 13 October 2007;   Accepted 20 February 2008
Online 20 June 2008

We describe the present status of the pion distribution amplitude (DA) as it originates from several sources: (i) a nonperturbative approach based on QCD sum rules with nonlocal condensates, (ii) an O(as) QCD analysis of the CLEO data on Fgg*p(Q2) with asymptotic and renormalon models for higher twists and (iii) recent high-precision lattice QCD calculations of the second moment of the pion DA. We show predictions for the pion electromagnetic form factor, obtained in analytic QCD perturbation theory, and compare it with the JLab data on Fp(Q2). We also discuss in this context an improved model for nonlocal condensates in QCD and show its consequences for the pion DA and the gg*®p transition form factor. We include a brief analysis of meson-induced massive lepton (muon) Drell-Yan production for the process p-N®m+m-X, considering both an unpolarized nucleon target and longitudinally polarized protons.

PACS numbers: 11.10.Hi, 12.38.Bx, 12.38.Lg, 13.40.Gp
UDC 539.125

Keywords: pion distribution amplitude, electromagnetic form factors, QCD sum rules, factorization, renormalization group evolution, lattice QCD, Drell-Yan production

Copyright by The Croatian Physical Society
For problems or questions please contact fizika@fizika.hfd.hr