# Light-Front Holography, AdS/QCD, and Hadronic Phenomena

## Abstract

AdS/QCD, the correspondence between theories in a modified five-dimensional anti-de Sitter space and confining field theories in physical space-time, provides a remarkable semiclassical model for hadron physics. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. We identify the AdS coordinate z with an invariant light-front coordinate {zeta} which separates the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schroedinger equation with a confining potential which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The mapping of electromagnetic and gravitational form factors in AdS space to their corresponding expressions in light-front theory confirms this correspondence. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. The distinction between static structure functions, such as the probability distributions computed from the square of the light-front wavefunctions, versus dynamical structure functions which include the effects of rescattering, is emphasized. A new method for computing the hadronization of quark andmore »

- Authors:

- Publication Date:

- Research Org.:
- Stanford Linear Accelerator Center (SLAC)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 969275

- Report Number(s):
- SLAC-PUB-13778

arXiv:0909.3899; TRN: US1000239

- DOE Contract Number:
- AC02-76SF00515

- Resource Type:
- Conference

- Resource Relation:
- Conference: Talk given at Light Cone 2009: Relativistic Hadronic and Particle Physics (LC 2009), Sao Jose dos Campos, Brazil, 8-13 Jul 2009

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; CONDENSATES; CONFINEMENT; DIMENSIONS; FIELD THEORIES; FORM FACTORS; GLUONS; HADRONS; HOLOGRAPHY; LIGHT CONE; ORBITAL ANGULAR MOMENTUM; PHYSICS; QUANTUM CHROMODYNAMICS; QUARKS; RESCATTERING; SCHROEDINGER EQUATION; SPIN; STRUCTURE FUNCTIONS; Phenomenology-HEP,HEPPH, HEPTH

### Citation Formats

```
Brodsky, Stanley J, /SLAC, de Teramond, Guy F, and /Costa Rica U.
```*Light-Front Holography, AdS/QCD, and Hadronic Phenomena*. United States: N. p., 2009.
Web.

```
Brodsky, Stanley J, /SLAC, de Teramond, Guy F, & /Costa Rica U.
```*Light-Front Holography, AdS/QCD, and Hadronic Phenomena*. United States.

```
Brodsky, Stanley J, /SLAC, de Teramond, Guy F, and /Costa Rica U. Wed .
"Light-Front Holography, AdS/QCD, and Hadronic Phenomena". United States. https://www.osti.gov/servlets/purl/969275.
```

```
@article{osti_969275,
```

title = {Light-Front Holography, AdS/QCD, and Hadronic Phenomena},

author = {Brodsky, Stanley J and /SLAC and de Teramond, Guy F and /Costa Rica U.},

abstractNote = {AdS/QCD, the correspondence between theories in a modified five-dimensional anti-de Sitter space and confining field theories in physical space-time, provides a remarkable semiclassical model for hadron physics. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. We identify the AdS coordinate z with an invariant light-front coordinate {zeta} which separates the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schroedinger equation with a confining potential which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The mapping of electromagnetic and gravitational form factors in AdS space to their corresponding expressions in light-front theory confirms this correspondence. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. The distinction between static structure functions, such as the probability distributions computed from the square of the light-front wavefunctions, versus dynamical structure functions which include the effects of rescattering, is emphasized. A new method for computing the hadronization of quark and gluon jets at the amplitude level, an event amplitude generator, is outlined.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2009},

month = {12}

}