AdS/QCD, LIight-Front Holography, and the Non-perturbative Running Coupling

Conference · Thu Apr 29 04:00:00 EDT 2010

OSTI ID:979043

Brodsky, Stanley J; de Teramond, Guy; Deur, Alexandre

The combination of Anti-de Sitter space (AdS) methods with light-front (LF) holography provides a remarkably accurate first approximation for the spectra and wavefunctions of meson and baryon light-quark bound states. The resulting bound-state Hamiltonian equation of motion in QCD leads to relativistic light-front wave equations in terms of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. These equations of motion in physical space-time are equivalent to the equations of motion which describe the propagation of spin-J modes in anti-de Sitter (AdS) space. The eigenvalues give the hadronic spectrum, and the eigenmodes represent the probability distributions of the hadronic constituents at a given scale. A positive-sign confining dilaton background modifying AdS space gives a very good account of meson and baryon spectroscopy and form factors. The light-front holographic mapping of this model also leads to a non-perturbative effective coupling {alpha}{sub s}{sup Ads} (Q{sup 2}) which agrees with the effective charge defined by the Bjorken sum rule and lattice simulations. It displays a transition from perturbative to nonperturbative conformal regimes at a momentum scale {approx} 1 GeV. The resulting {beta}-function appears to capture the essential characteristics of the full {beta}-function of QCD, thus giving further support to the application of the gauge/gravity duality to the confining dynamics of strongly coupled QCD.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 979043
• Report Number(s): SLAC-PUB-13998; arXiv:1002.4660
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
APPROXIMATIONS
BARYON SPECTROSCOPY
BARYONS
BOUND STATE
DUALITY
EFFECTIVE CHARGE
EIGENVALUES
EQUATIONS OF MOTION
FORM FACTORS
HADRONS
HAMILTONIANS
HOLOGRAPHY
MESONS
PROBABILITY
Phenomenology-HEP
HEPPH
HEPTH
QUANTUM CHROMODYNAMICS
QUARKS
SPACE-TIME
SPECTRA
SUM RULES
WAVE EQUATIONS