# QCD Phenomenology and Light-Front Wavefunctions

## Abstract

A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, diffractive dissociation into jets, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. Light-front quantization can also be used in the Hamiltonian form to construct an event generator for high energy physics reactions at the amplitude level. The light-cone partition function, summed over exponentially weighted light-cone energies, has simple boost properties which may be useful for studies in heavy ion collisions. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection to light-front probability distributions. In particular, the shadowingmore »

- Authors:

- Publication Date:

- Research Org.:
- Stanford Linear Accelerator Center, Menlo Park, CA (US)

- Sponsoring Org.:
- USDOE Office of Energy Research (ER) (US)

- OSTI Identifier:
- 798925

- Report Number(s):
- SLAC-PUB-9056

TRN: US0205091

- DOE Contract Number:
- AC03-76SF00515

- Resource Type:
- Technical Report

- Resource Relation:
- Other Information: PBD: 21 Nov 2001

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; BOUND STATE; COMPTON EFFECT; DEGREES OF FREEDOM; HEAVY IONS; HIGH ENERGY PHYSICS; LIGHT CONE; MOMENTUM TRANSFER; NUCLEAR STRUCTURE; PARTITION FUNCTIONS; QUANTUM CHROMODYNAMICS; QUANTUM FIELD THEORY; STRUCTURE FUNCTIONS

### Citation Formats

```
Brodsky, Stanley J.
```*QCD Phenomenology and Light-Front Wavefunctions*. United States: N. p., 2001.
Web. doi:10.2172/798925.

```
Brodsky, Stanley J.
```*QCD Phenomenology and Light-Front Wavefunctions*. United States. doi:10.2172/798925.

```
Brodsky, Stanley J. Wed .
"QCD Phenomenology and Light-Front Wavefunctions". United States. doi:10.2172/798925. https://www.osti.gov/servlets/purl/798925.
```

```
@article{osti_798925,
```

title = {QCD Phenomenology and Light-Front Wavefunctions},

author = {Brodsky, Stanley J.},

abstractNote = {A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, diffractive dissociation into jets, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. Light-front quantization can also be used in the Hamiltonian form to construct an event generator for high energy physics reactions at the amplitude level. The light-cone partition function, summed over exponentially weighted light-cone energies, has simple boost properties which may be useful for studies in heavy ion collisions. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection to light-front probability distributions. In particular, the shadowing of nuclear structure functions is due to destructive interference effects from leading-twist diffraction of the virtual photon, physics not included in the nuclear light-cone wavefunctions.},

doi = {10.2172/798925},

journal = {},

number = ,

volume = ,

place = {United States},

year = {Wed Nov 21 00:00:00 EST 2001},

month = {Wed Nov 21 00:00:00 EST 2001}

}