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, qπ(x); namely, at a characteristic hadronic scale, qπ(x)~(1-x)2 for x≳0.85; and the valence-quarks carry approximately two-thirds of the pion's light-front momentum.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- Grant/Contract Number:
- AC02-06CH11357; FL0992247; 3034 PH-QCD; 283286; ANR-12-MONU-0008-01; FPA2011-23781; NSF-PHY1206187
- OSTI ID:
- 1227769
- Alternate ID(s):
- OSTI ID: 1214227
- Journal Information:
- Physics Letters B, Journal Name: Physics Letters B Vol. 737 Journal Issue: C; ISSN 0370-2693
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- Netherlands
- Language:
- English
Web of Science
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