Parton Skewed Distributions in the Pion and Quark-Hadron Duality

Abstract

Applying arguments based on the operator product expansion for a three-point correlator and relying on quark-hadron duality, we derive an expression for the skewed (non-forward) parton distribution in the pion in the case of a zero-skewedness parameter, {\cal F}^{ψ|π}_{ζ=0}(X;t). We expect that our result is relevant for moderately large momentum transfers 1 < t < 10 GeV^2. In addition, we construct a purely phenomenological factorized model for the same quantity in close analogy to Radyushkin's model, originally proposed for skewed distributions of quarks in the nucleon. Though the quark-hadron duality approach supports theoretically the factorized model, the two models exhibit a different behavior in the parton momentum fraction X at any fixed t. The relevant process to distinguish between the two options seems to be the WACS off the pion that measures (to leading t/s-order) the inverse moment <X^{-1}> of the skewed distribution. Even after the inclusion of the first order kinematic t/s-corrections, the predictions for the cross section \frac{d σ}{d t}(s,t) at c.m.s. scattering angles \vartheta=30^{\circ} and 90^{\circ} differ by factors 3.5--3.9 and 2.9--7.5, respectively, so that a discrimination appears possible.

16 pages, LaTeX, 9 eps figures, revtex, aps, floats, psbox.tex, corrected typos, changed slightly text, version to be published in Phys.Rev.D

References in corpus (4)

• Skewed and double distributions in pion and nucleon
• Pionic Parton Distributions Revisited
• Symmetries and structure of skewed and double distributions
• Skewed Parton Distributions in Real and Virtual Compton Scattering

Cited by in corpus (13)

• Generalized Parton Distributions
• Generalized parton distributions of the pion in chiral quark models and their QCD evolution
• Gravitational and higher-order form factors of the pion in chiral quark models
• From Bethe-Salpeter Wave Functions to Generalised Parton Distributions
• Deeply virtual Compton scattering on a virtual pion target
• Generalized Quark Transversity Distribution of the Pion in Chiral Quark Models
• Transversity form factors of the pion in chiral quark models
• The skewed quark distribution of the pion at large momentum transfer
• A note on the QCD evolution of generalized form factors
• Generalized quasi, Ioffe-time, and pseudo quark distributions of the pion in the Nambu--Jona-Lasinio model
• Skewed parton distributions and the scale dependence of the transverse size parameter
• QCD Sum Rules and Models for Generalized Parton Distributions
• Photon interactions and chiral dynamics