# Light-Front Quantization and AdS/QCD: An Overview

## Abstract

We give an overview of the light-front holographic approach to strongly coupled QCD, whereby a confining gauge theory, quantized on the light front, is mapped to a higher-dimensional anti de Sitter (AdS) space. The framework is guided by the AdS/CFT correspondence incorporating a gravitational background asymptotic to AdS space which encodes the salient properties of QCD, such as the ultraviolet conformal limit at the AdS boundary at z {yields} 0, as well as modifications of the geometry in the large z infrared region to describe confinement and linear Regge behavior. There are two equivalent procedures for deriving the AdS/QCD equations of motion: one can start from the Hamiltonian equation of motion in physical space time by studying the off-shell dynamics of the bound state wavefunctions as a function of the invariant mass of the constituents. To a first semiclassical approximation, where quantum loops and quark masses are not included, this leads to a light-front Hamiltonian equation which describes the bound state dynamics of light hadrons in terms of an invariant impact variable {zeta} which measures the separation of the partons within the hadron at equal light-front time. Alternatively, one can start from the gravity side by studying the propagation ofmore »

- Authors:

- Publication Date:

- Research Org.:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1022479

- Report Number(s):
- SLAC-PUB-14393

arXiv:1103.1100; TRN: US1104238

- DOE Contract Number:
- AC02-76SF00515

- Resource Type:
- Conference

- Journal Name:
- J.Phys.Conf.Ser.287:012007,2011

- Additional Journal Information:
- Conference: InvitedThe XIV Mexican School on Particles and Fields, of Morelia, Michoacan, Mexico, 11/8/2010-11/12/2010

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANGULAR MOMENTUM; BOUND STATE; CONFINEMENT; EDUCATIONAL FACILITIES; EQUATIONS OF MOTION; GEOMETRY; HADRONS; HAMILTONIANS; HOLOGRAPHY; MODIFICATIONS; QUANTIZATION; QUANTUM CHROMODYNAMICS; QUARKS; SEMICLASSICAL APPROXIMATION; SPACE-TIME; TRANSITION AMPLITUDES; Phenomenology-HEP, Theory-HEP,HEPPH, HEPTH

### Citation Formats

```
de Teramond, Guy F, /Costa Rica U., Brodsky, Stanley J, and /SLAC /Stanford U., Phys. Dept.
```*Light-Front Quantization and AdS/QCD: An Overview*. United States: N. p., 2011.
Web.

```
de Teramond, Guy F, /Costa Rica U., Brodsky, Stanley J, & /SLAC /Stanford U., Phys. Dept.
```*Light-Front Quantization and AdS/QCD: An Overview*. United States.

```
de Teramond, Guy F, /Costa Rica U., Brodsky, Stanley J, and /SLAC /Stanford U., Phys. Dept. Fri .
"Light-Front Quantization and AdS/QCD: An Overview". United States. https://www.osti.gov/servlets/purl/1022479.
```

```
@article{osti_1022479,
```

title = {Light-Front Quantization and AdS/QCD: An Overview},

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

abstractNote = {We give an overview of the light-front holographic approach to strongly coupled QCD, whereby a confining gauge theory, quantized on the light front, is mapped to a higher-dimensional anti de Sitter (AdS) space. The framework is guided by the AdS/CFT correspondence incorporating a gravitational background asymptotic to AdS space which encodes the salient properties of QCD, such as the ultraviolet conformal limit at the AdS boundary at z {yields} 0, as well as modifications of the geometry in the large z infrared region to describe confinement and linear Regge behavior. There are two equivalent procedures for deriving the AdS/QCD equations of motion: one can start from the Hamiltonian equation of motion in physical space time by studying the off-shell dynamics of the bound state wavefunctions as a function of the invariant mass of the constituents. To a first semiclassical approximation, where quantum loops and quark masses are not included, this leads to a light-front Hamiltonian equation which describes the bound state dynamics of light hadrons in terms of an invariant impact variable {zeta} which measures the separation of the partons within the hadron at equal light-front time. Alternatively, one can start from the gravity side by studying the propagation of hadronic modes in a fixed effective gravitational background. Both approaches are equivalent in the semiclassical approximation. This allows us to identify the holographic variable z in AdS space with the impact variable {zeta}. Light-front holography thus allows a precise mapping of transition amplitudes from AdS to physical space-time. The internal structure of hadrons is explicitly introduced and the angular momentum of the constituents plays a key role.},

doi = {},

journal = {J.Phys.Conf.Ser.287:012007,2011},

number = ,

volume = ,

place = {United States},

year = {2011},

month = {8}

}