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

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 themore » 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.« less
Authors:
; ; ; ; ;
Publication Date:
OSTI Identifier:
979043
Report Number(s):
SLAC-PUB-13998
arXiv:1002.4660; TRN: US1003079
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Invited talk at International Workshop on Strong Coupling Gauge Theories in LHC Era: SCGT 09, Nagoya, Japan, 8-11 Dec 2009
Research Org:
SLAC National Accelerator Laboratory (SLAC)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; BARYON SPECTROSCOPY; BARYONS; BOUND STATE; DUALITY; EFFECTIVE CHARGE; EIGENVALUES; EQUATIONS OF MOTION; FORM FACTORS; HADRONS; HAMILTONIANS; HOLOGRAPHY; MESONS; PROBABILITY; QUANTUM CHROMODYNAMICS; QUARKS; SPACE-TIME; SPECTRA; SUM RULES; WAVE EQUATIONS Phenomenology-HEP,HEPPH, HEPTH