Fock space distributions, structure functions, higher twists, and small x

Journal Article · Sat May 01 04:00:00 EDT 1999 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.59.094002· OSTI ID:336717

McLerran, L ^[1]; Venugopalan, R ^[2]

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1. Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)
2. Niels Bohr Institute, Blegdamsvej 17, Copenhagen, DK-2100 (Denmark)

We compute quark structure functions and the intrinsic Fock space distribution of sea quarks in a hadron wave function at small x. The computation is performed in an effective theory at small x where the gluon field is treated classically. At Q{sup 2} large compared to an intrinsic scale associated with the density of gluons {mu}{sup 2}, large compared to the QCD scale {Lambda}{sub QCD}{sup 2}, and large compared to the quark mass squared M{sup 2}, the Fock space distribution of quarks is identical to the distribution function measured in deep inelastic scattering. For Q{sup 2}{le}M{sup 2} but Q{sup 2}{gt}{mu}{sup 2}, the quark distribution is computed in terms of the gluon distribution function and explicit expressions are obtained. For Q{sup 2}{le}{mu}{sup 2} but Q{sup 2}{gt}{Lambda}{sub QCD}{sup 2} we obtain formal expressions for the quark distribution functions in terms of the glue. An evaluation of these requires a renormalization group analysis of the gluon distribution function in the regime of high parton density. For light quarks at high Q{sup 2}, the DGLAP flavor singlet evolution equations for the parton distributions are recovered. Explicit expressions are given for heavy quark structure functions at small x. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 336717
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 9 Vol. 59; ISSN 0556-2821; ISSN PRVDAQ
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DEEP INELASTIC SCATTERING
GLUONS
PARTON MODEL
QUANTUM CHROMODYNAMICS
QUARK MODEL
QUARKS
RENORMALIZATION
STRUCTURE FUNCTIONS
WAVE FUNCTIONS