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Title: High-energy photon-nucleon and photon-nucleus cross sections

Abstract

We reexamine the theory of hadronic photon-nucleon interactions at the quark-gluon level. The possibility of multiple parton collisions in a single photon-nucleon collision requires an eikonal treatment of the high-energy scattering process. We give a general formulation of the theory in which the [gamma][ital p] cross section is expressed as a sum over properly eikonalized cross sections for the interaction of the virtual hadronic components of the photon with the proton, with each cross section weighted by the probability with which that component appears in the photon, and then develop a detailed model which includes contributions from light vector mesons and from excited virtual states described in a quark-gluon basis. The parton distribution functions which appear can be related approximately to those in the pion, while a weighted sum gives the distribution functions for the photon. We use the model to make improved QCD-based predictions for the total inelastic photon-nucleon and photon-nucleus cross sections at energies relevant for DESY HERA experiments and cosmic-ray observations. We emphasize the importance in this procedure of including a soft-scattering background such that the calculated cross sections join smoothly with low-energy data. Our results show clearly that high-energy measurements of the total inelastic [gamma][ital p]more » cross section can impose strong constraints on the gluon and quark distributions in the photon, and indirectly on those in the pion.« less

Authors:
;  [1];  [2];  [3];  [4]
  1. Department of Physics, University of Wisconsin enMadison, Madison, Wisconsin 53706 (United States)
  2. Department of Physics, Texas A M University, College Station, Texas 77843 (United States)
  3. Department of Theoretical Physics, University of Lund, Lund, Sweden S-22362 ( )
  4. Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)
Publication Date:
OSTI Identifier:
7368810
DOE Contract Number:  
AC02-76ER00881; FG02-85ER40213
Resource Type:
Journal Article
Journal Name:
Physical Review, D (Particles Fields); (United States)
Additional Journal Information:
Journal Volume: 48:3; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; PHOTON-NUCLEON INTERACTIONS; CROSS SECTIONS; INELASTIC SCATTERING; COSMIC RADIATION; DESY; DISTRIBUTION FUNCTIONS; EIKONAL APPROXIMATION; GLUONS; PHOTON-PROTON INTERACTIONS; PHOTONUCLEAR REACTIONS; PROBABILITY; QUANTUM CHROMODYNAMICS; QUARK MODEL; ACCELERATORS; BASIC INTERACTIONS; BOSONS; COMPOSITE MODELS; CYCLIC ACCELERATORS; ELECTROMAGNETIC INTERACTIONS; ELEMENTARY PARTICLES; FIELD THEORIES; FUNCTIONS; INTERACTIONS; IONIZING RADIATIONS; MATHEMATICAL MODELS; NUCLEAR REACTIONS; PARTICLE INTERACTIONS; PARTICLE MODELS; PHOTON-BARYON INTERACTIONS; PHOTON-HADRON INTERACTIONS; POSTULATED PARTICLES; QUANTUM FIELD THEORY; RADIATIONS; SCATTERING; SYNCHROTRONS; 662330* - Photon & Charged-Lepton Interactions with Hadrons- (1992)

Citation Formats

Honjo, K, Durand, L, Gandhi, R, Pi, H, and Sarcevic, I. High-energy photon-nucleon and photon-nucleus cross sections. United States: N. p., 1993. Web. doi:10.1103/PhysRevD.48.1048.
Honjo, K, Durand, L, Gandhi, R, Pi, H, & Sarcevic, I. High-energy photon-nucleon and photon-nucleus cross sections. United States. https://doi.org/10.1103/PhysRevD.48.1048
Honjo, K, Durand, L, Gandhi, R, Pi, H, and Sarcevic, I. 1993. "High-energy photon-nucleon and photon-nucleus cross sections". United States. https://doi.org/10.1103/PhysRevD.48.1048.
@article{osti_7368810,
title = {High-energy photon-nucleon and photon-nucleus cross sections},
author = {Honjo, K and Durand, L and Gandhi, R and Pi, H and Sarcevic, I},
abstractNote = {We reexamine the theory of hadronic photon-nucleon interactions at the quark-gluon level. The possibility of multiple parton collisions in a single photon-nucleon collision requires an eikonal treatment of the high-energy scattering process. We give a general formulation of the theory in which the [gamma][ital p] cross section is expressed as a sum over properly eikonalized cross sections for the interaction of the virtual hadronic components of the photon with the proton, with each cross section weighted by the probability with which that component appears in the photon, and then develop a detailed model which includes contributions from light vector mesons and from excited virtual states described in a quark-gluon basis. The parton distribution functions which appear can be related approximately to those in the pion, while a weighted sum gives the distribution functions for the photon. We use the model to make improved QCD-based predictions for the total inelastic photon-nucleon and photon-nucleus cross sections at energies relevant for DESY HERA experiments and cosmic-ray observations. We emphasize the importance in this procedure of including a soft-scattering background such that the calculated cross sections join smoothly with low-energy data. Our results show clearly that high-energy measurements of the total inelastic [gamma][ital p] cross section can impose strong constraints on the gluon and quark distributions in the photon, and indirectly on those in the pion.},
doi = {10.1103/PhysRevD.48.1048},
url = {https://www.osti.gov/biblio/7368810}, journal = {Physical Review, D (Particles Fields); (United States)},
issn = {0556-2821},
number = ,
volume = 48:3,
place = {United States},
year = {Sun Aug 01 00:00:00 EDT 1993},
month = {Sun Aug 01 00:00:00 EDT 1993}
}