# Hadron production in photon-photon collisions. [Cross sections, structure functions, light cone, parton and vector dominance model, sum rules, helicity analysis, quark model, scaling]

## Abstract

We analyze deep-inelastic photon-photon collisions via the two-photon mechanism in electron-positron (-electron) colliding beams in a form especially suitable for experimental analysis. It is shown that by a helicity analysis similar to that used in electroproduction experiments, we can separate five of the eight structure functions describing the process ..gamma..* + ..gamma..* ..-->.. hadrons. The helicity cross sections for this process and for the process with one real photon (inelastic electron-photon scattering) are related to structure functions, and are evaluated using quark light-cone algebra. There are anomalous contributions to the structure functions for the inelastic electron-photon scattering which arise both in parton as well as generalized vector-meson-dominance models. This suggests a connection between these two types of models for photon-photon scattering. Further, we use vector-meson dominance to construct a sum rule for sigma/sub gamma//sub gamma/ /sub arrow-right/ from which it is estimated that roughly 20% of the cross section should be built up from higher-mass vector states. Using a spectral representation for the total transverse cross section, and the ''aligned-jet'' vector-dominance model we achieve a connection, via a ''correspondence principle,'' with the parton model for the hadron multiplicities in photon-photon collisions. We also comment on inclusive pion multiplicities and themore »

- Authors:

- Publication Date:

- Research Org.:
- Department of Physics, Kashmir University, Srinagar 190006, India

- OSTI Identifier:
- 7342689

- Resource Type:
- Journal Article

- Journal Name:
- Phys. Rev., D; (United States)

- Additional Journal Information:
- Journal Volume: 14:3

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRON-POSITRON INTERACTIONS; DEEP INELASTIC SCATTERING; HADRONS; MULTIPLE PRODUCTION; PHOTON-PHOTON INTERACTIONS; INCLUSIVE INTERACTIONS; CROSS SECTIONS; HELICITY; PARTICLE PRODUCTION; QUARK MODEL; SCALE INVARIANCE; STRUCTURE FUNCTIONS; VECTOR DOMINANCE MODEL; BASIC INTERACTIONS; COMPOSITE MODELS; ELECTROMAGNETIC INTERACTIONS; ELEMENTARY PARTICLES; FUNCTIONS; INELASTIC SCATTERING; INTERACTIONS; INVARIANCE PRINCIPLES; LEPTON-BARYON INTERACTIONS; LEPTON-HADRON INTERACTIONS; LEPTON-LEPTON INTERACTIONS; LEPTON-NUCLEON INTERACTIONS; MATHEMATICAL MODELS; PARTICLE INTERACTIONS; PARTICLE MODELS; PARTICLE PROPERTIES; SCATTERING; 645202* - High Energy Physics- Particle Interactions & Properties-Theoretical- Electromagnetic Interactions & Properties

### Citation Formats

```
Pandita, P N, and Singh, Y.
```*Hadron production in photon-photon collisions. [Cross sections, structure functions, light cone, parton and vector dominance model, sum rules, helicity analysis, quark model, scaling]*. United States: N. p., 1976.
Web. doi:10.1103/PhysRevD.14.739.

```
Pandita, P N, & Singh, Y.
```*Hadron production in photon-photon collisions. [Cross sections, structure functions, light cone, parton and vector dominance model, sum rules, helicity analysis, quark model, scaling]*. United States. https://doi.org/10.1103/PhysRevD.14.739

```
Pandita, P N, and Singh, Y. 1976.
"Hadron production in photon-photon collisions. [Cross sections, structure functions, light cone, parton and vector dominance model, sum rules, helicity analysis, quark model, scaling]". United States. https://doi.org/10.1103/PhysRevD.14.739.
```

```
@article{osti_7342689,
```

title = {Hadron production in photon-photon collisions. [Cross sections, structure functions, light cone, parton and vector dominance model, sum rules, helicity analysis, quark model, scaling]},

author = {Pandita, P N and Singh, Y},

abstractNote = {We analyze deep-inelastic photon-photon collisions via the two-photon mechanism in electron-positron (-electron) colliding beams in a form especially suitable for experimental analysis. It is shown that by a helicity analysis similar to that used in electroproduction experiments, we can separate five of the eight structure functions describing the process ..gamma..* + ..gamma..* ..-->.. hadrons. The helicity cross sections for this process and for the process with one real photon (inelastic electron-photon scattering) are related to structure functions, and are evaluated using quark light-cone algebra. There are anomalous contributions to the structure functions for the inelastic electron-photon scattering which arise both in parton as well as generalized vector-meson-dominance models. This suggests a connection between these two types of models for photon-photon scattering. Further, we use vector-meson dominance to construct a sum rule for sigma/sub gamma//sub gamma/ /sub arrow-right/ from which it is estimated that roughly 20% of the cross section should be built up from higher-mass vector states. Using a spectral representation for the total transverse cross section, and the ''aligned-jet'' vector-dominance model we achieve a connection, via a ''correspondence principle,'' with the parton model for the hadron multiplicities in photon-photon collisions. We also comment on inclusive pion multiplicities and the approach to scaling for photon-photon processes in the light-cone algebra. (AIP)},

doi = {10.1103/PhysRevD.14.739},

url = {https://www.osti.gov/biblio/7342689},
journal = {Phys. Rev., D; (United States)},

number = ,

volume = 14:3,

place = {United States},

year = {1976},

month = {8}

}