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Title: Exclusive processes in perturbative quantum chromodynamics

Abstract

We present a systematic analysis in perturbative quantum chromodynamics (QCD) of large-momentum-transfer exclusive processes. Predictions are given for the scaling behavior, angular dependence, helicity structure, and normalization of elastic and inelastic form factors and large-angle exclusive scattering amplitudes for hadrons and photons. We prove that these reactions are dominated by quark and gluon subprocesses at short distances, and thus that the dimensional-counting rules for the power-law falloff of these amplitudes with momentum transfer are rigorous predictions of QCD, modulo calculable logarithmic corrections from the behavior of the hadronic wave functions at short distances. These anomalous-dimension corrections are determined by evolution equations for process-independent meson and baryon ''distribution amplitudes'' phi(x/sub i/,Q) which control the valence-quark distributions in high-momentum-transfer exclusive reactions. The analysis can be carried out systematically in powers of ..cap alpha../sub s/(Q/sup 2/), the QCD running coupling constant. Although the calculations are most conveniently carried out using light-cone perturbation theory and the light-cone gauge, we also present a gauge-independent analysis and relate the distribution amplitude to a gauge-invariant Bethe-Salpeter amplitude.

Authors:
;
Publication Date:
Research Org.:
Laboratory of Nuclear Studies, Cornell University, Ithaca, New York 14853
OSTI Identifier:
6804368
Alternate Identifier(s):
OSTI ID: 6804368
DOE Contract Number:  
DE-AC03-76SF00515
Resource Type:
Journal Article
Journal Name:
Phys. Rev., D; (United States)
Additional Journal Information:
Journal Volume: 22:9
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; HADRONS; ELASTIC SCATTERING; INELASTIC SCATTERING; PHOTONS; QUANTUM CHROMODYNAMICS; EXCLUSIVE INTERACTIONS; BETHE-SALPETER EQUATION; FORM FACTORS; GAUGE INVARIANCE; GLUONS; HELICITY; LIGHT CONE; MOMENTUM TRANSFER; PERTURBATION THEORY; QUARKS; SCALING LAWS; SCATTERING AMPLITUDES; AMPLITUDES; ELEMENTARY PARTICLES; EQUATIONS; FIELD THEORIES; INTERACTIONS; INVARIANCE PRINCIPLES; MASSLESS PARTICLES; PARTICLE INTERACTIONS; PARTICLE PROPERTIES; POSTULATED PARTICLES; QUANTUM FIELD THEORY; SCATTERING; SPACE-TIME 645400* -- High Energy Physics-- Field Theory; 645202 -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Electromagnetic Interactions & Properties; 645204 -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties

Citation Formats

Lepage, G.P., and Brodsky, S.J. Exclusive processes in perturbative quantum chromodynamics. United States: N. p., 1980. Web. doi:10.1103/PhysRevD.22.2157.
Lepage, G.P., & Brodsky, S.J. Exclusive processes in perturbative quantum chromodynamics. United States. doi:10.1103/PhysRevD.22.2157.
Lepage, G.P., and Brodsky, S.J. Sat . "Exclusive processes in perturbative quantum chromodynamics". United States. doi:10.1103/PhysRevD.22.2157.
@article{osti_6804368,
title = {Exclusive processes in perturbative quantum chromodynamics},
author = {Lepage, G.P. and Brodsky, S.J.},
abstractNote = {We present a systematic analysis in perturbative quantum chromodynamics (QCD) of large-momentum-transfer exclusive processes. Predictions are given for the scaling behavior, angular dependence, helicity structure, and normalization of elastic and inelastic form factors and large-angle exclusive scattering amplitudes for hadrons and photons. We prove that these reactions are dominated by quark and gluon subprocesses at short distances, and thus that the dimensional-counting rules for the power-law falloff of these amplitudes with momentum transfer are rigorous predictions of QCD, modulo calculable logarithmic corrections from the behavior of the hadronic wave functions at short distances. These anomalous-dimension corrections are determined by evolution equations for process-independent meson and baryon ''distribution amplitudes'' phi(x/sub i/,Q) which control the valence-quark distributions in high-momentum-transfer exclusive reactions. The analysis can be carried out systematically in powers of ..cap alpha../sub s/(Q/sup 2/), the QCD running coupling constant. Although the calculations are most conveniently carried out using light-cone perturbation theory and the light-cone gauge, we also present a gauge-independent analysis and relate the distribution amplitude to a gauge-invariant Bethe-Salpeter amplitude.},
doi = {10.1103/PhysRevD.22.2157},
journal = {Phys. Rev., D; (United States)},
number = ,
volume = 22:9,
place = {United States},
year = {1980},
month = {11}
}