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Title: Basic features of the pion valence-quark distribution function

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 π(x); namely, at a characteristic hadronic scale, q π(x)~(1-x) 2 for x≳0.85; and the valence-quarks carry approximately two-thirds of the pion's light-front momentum.
 [1] ;  [2] ;  [2] ; ORCiD logo [3] ;  [4] ;  [5]
  1. Univ. of Adelaide, Adelaide, SA (Australia)
  2. IRFU/Service de Physique Nucleaire, Gif-sur-Yvette (France)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Univ. de Huelva, Huelva (Spain)
  5. Kent State Univ., Kent, OH (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
AC02-06CH11357; FL0992247; 3034 PH-QCD; 283286; ANR-12-MONU-0008-01; FPA2011-23781; NSF-PHY1206187
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 737; Journal Issue: C; Journal ID: ISSN 0370-2693
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; deep inelastic scattering; Drell–Yan process; dynamical chiral symmetry breaking; Dyson–Schwinger equations; π-meson; parton distribution functions