Light-Front Quantization Approach to the Gauge-Gravity Correspondence and Hadron Spectroscopy

TL;DR

This paper establishes a correspondence between semiclassical light-front QCD and a dual gravity model in AdS space, leading to a new approach for modeling hadron spectra and wavefunctions in strongly coupled regimes.

Contribution

It introduces light-front holography as a novel method to derive relativistic bound-state equations from a gravity dual, providing analytical tools for hadron spectroscopy.

Findings

Eigenvalues match observed meson and baryon spectra

Derived light-front wavefunctions describe hadronic structure

Extended algebraic methods to include confinement

Abstract

We find a correspondence between semiclassical QCD quantized on the light-front and a dual gravity model in anti--de Sitter (AdS) space, thus providing an initial approximation to QCD in its strongly coupled regime. This correspondence -- light-front holography -- leads to a light-front Hamiltonian and relativistic bound-state wave equations that are functions of an invariant impact variable $\zeta$ which measures the separation of the quark and gluonic constituents within hadrons at equal light-front time. The eigenvalues of the resulting light-front Schr\"odinger and Dirac equations are consistent with the observed light meson and baryon spectrum, and the eigenmodes provide the light-front wavefunctions, the probability amplitudes describing the dynamics of the hadronic constituents. The light-front equations of motion, which are dual to an effective classical gravity theory, possess remarkable algebraic and integrability properties which are dictated by the underlying conformal properties of the theory. We extend the algebraic construction to include a confining potential while preserving the integrability of the mesonic and baryonic bound-state equations.