# Infrared and high energy fixed angle domains of scattering and the role of Eikonal approximation

## Abstract

We examine the infrared structure and fixed angle behavior of generalised ladder diagrams in spinor electrodynamics. The external line rules for infrared divergence is proved within the framework of parametric representation of the amplitudes. We derive as set of rules for computing the precise form of the leading infrared behaviour of any generalised ladder diagram. The same set of rules is shown to yield the leading term in the high energy fixed angle limit. Our analysis shows that both in the infrared and in the fixed-angle high energy limits the usual propagator eikonal approximation fails even in the leading order. The deficiencies of eikonal approximation can be partially removed if one aslo makes the small angle approximation. Leading corrections of relative O (vertical-bartvertical-bar/sup 1/2/s/sup 1/2/) to the small-angle eikonal amplitude are calculated.

- Authors:

- Publication Date:

- Research Org.:
- Saha Institute of Nuclear Physics, Calcutta-700009, India

- OSTI Identifier:
- 6246470

- Resource Type:
- Journal Article

- Journal Name:
- Ann. Phys. (N.Y.); (United States)

- Additional Journal Information:
- Journal Volume: 117:2

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; QUANTUM ELECTRODYNAMICS; EIKONAL APPROXIMATION; INFRARED DIVERGENCES; LADDER APPROXIMATION; SCATTERING AMPLITUDES; SPINORS; AMPLITUDES; ELECTRODYNAMICS; FIELD THEORIES; QUANTUM FIELD THEORY; 645400* - High Energy Physics- Field Theory

### Citation Formats

```
Banerjee, H., and Sharma, S.K.
```*Infrared and high energy fixed angle domains of scattering and the role of Eikonal approximation*. United States: N. p., 1979.
Web. doi:10.1016/0003-4916(79)90364-6.

```
Banerjee, H., & Sharma, S.K.
```*Infrared and high energy fixed angle domains of scattering and the role of Eikonal approximation*. United States. doi:10.1016/0003-4916(79)90364-6.

```
Banerjee, H., and Sharma, S.K. Thu .
"Infrared and high energy fixed angle domains of scattering and the role of Eikonal approximation". United States. doi:10.1016/0003-4916(79)90364-6.
```

```
@article{osti_6246470,
```

title = {Infrared and high energy fixed angle domains of scattering and the role of Eikonal approximation},

author = {Banerjee, H. and Sharma, S.K.},

abstractNote = {We examine the infrared structure and fixed angle behavior of generalised ladder diagrams in spinor electrodynamics. The external line rules for infrared divergence is proved within the framework of parametric representation of the amplitudes. We derive as set of rules for computing the precise form of the leading infrared behaviour of any generalised ladder diagram. The same set of rules is shown to yield the leading term in the high energy fixed angle limit. Our analysis shows that both in the infrared and in the fixed-angle high energy limits the usual propagator eikonal approximation fails even in the leading order. The deficiencies of eikonal approximation can be partially removed if one aslo makes the small angle approximation. Leading corrections of relative O (vertical-bartvertical-bar/sup 1/2/s/sup 1/2/) to the small-angle eikonal amplitude are calculated.},

doi = {10.1016/0003-4916(79)90364-6},

journal = {Ann. Phys. (N.Y.); (United States)},

number = ,

volume = 117:2,

place = {United States},

year = {1979},

month = {2}

}