Basic features of the pion valence-quark distribution function

Abstract

The impulse-approximation expression used hitherto to define the pion's valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression produces the model-independent result that quarks dressed via the rainbow-ladder truncation, or any practical analogue, carry all the pion's light-front momentum at a characteristic hadronic scale. Corrections to the leading contribution may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea-quarks. Working with available empirical information, we use an algebraic model to express the principal impact of both classes of corrections. This enables a realistic comparison with experiment that allows us to highlight the basic features of the pion's measurable valence-quark distribution, $q^{\pi }(x)$; namely, at a characteristic hadronic scale, $q^{\pi }(x)\sim (1-x{)}^2$ for $x\gtrsim 0.85$; and the valence-quarks carry approximately two-thirds of the pion's light-front momentum.

7 pages, 5 figures

References in corpus (6)

• Chiral effective field theory and nuclear forces
• Sketching the Bethe-Salpeter kernel
• Soft-Gluon Resummation and the Valence Parton Distribution Function of the Pion
• Distribution Functions of the Nucleon and Pion in the Valence Region
• Abelian anomaly and neutral pion production
• Pion and kaon valence-quark parton distribution functions

Cited by in corpus (2)

• Nucleon tensor charges and electric dipole moments
• Towards a Pion Generalized Parton Distribution Model from Dyson-Schwinger Equations