N. G. Stefanis

QCD-based pion distribution amplitudes confronting experimental data

Abstract We use QCD sum rules with non-local condensates to recalculate more accurately the moments and their confidence intervals of the twist-2 pion distribution amplitude including radiative corrections. We are thus able to construct an admissible set of pion distribution amplitudes which define a reliability region in the a 2 , a 4 plane of the Gegenbauer polynomial expansion coefficients. We emphasize that models like that of Chernyak and Zhitnitsky, as well as the asymptotic solution, are excluded from this set. We show that the determined a 2 , a 4 region strongly overlaps with that extracted from the CLEO data by Schmedding and Yakovlev and that this region is also not far from the results of the first direct measurement of the pion valence quark momentum distribution by the Fermilab E791 Collaboration. Comparisons with recent lattice calculations and instanton-based models are briefly discussed.

Pion form factor in QCD: From nonlocal condensates to next-to-leading-order analytic perturbation theory

We present an investigation of the pions electromagnetic form factor

Wilson lines and transverse-momentum dependent parton distribution functions: A Renormalization-group analysis

{F}_{\ensuremath{\pi}}{(Q}^{2})

Unbiased analysis of CLEO data at NLO and the pion distribution amplitude

in the spacelike region utilizing two new ingredients: (i) a double-humped, end-point-suppressed pion distribution amplitude derived before via QCD sum rules with nonlocal condensates\char22{}found to comply at the

Pion form-factors with improved infrared factorization

1\ensuremath{\sigma}

Transition form factors of the pion in light-cone QCD sum rules with next-to-next-to-leading order contributions

level with the CLEO data on the

Electromagnetic form factors of the nucleon from perturbative QCD and QCD sum rules

\ensuremath{\pi}\ensuremath{\gamma}

Analyticity and power corrections in hard-scattering hadronic functions

transition\char22{}and (ii) analytic perturbation theory at the level of parton amplitudes for hadronic reactions. The computation of

Worldline approach to Sudakov-type form factors in non-Abelian gauge theories

{F}_{\ensuremath{\pi}}{(Q}^{2})

Neutron form factor: Sudakov suppression and intrinsic transverse size effect

within this approach is performed at the next to leading order (NLO) of QCD perturbation theory (standard and analytic), including the evolution of the pion distribution amplitude at the same order. We consider the NLO corrections to the form factor in the