QCD and Light-Front Dynamics

Conference · Mon Jan 10 04:00:00 EST 2011

OSTI ID:1002997

Brodsky, Stanley J; de Teramond, Guy F

AdS/QCD, the correspondence between theories in a dilaton-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. The result is a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time and determines the off-shell dynamics of the bound state wavefunctions as a function of the invariant mass of the constituents. The hadron eigenstates generally have components with different orbital angular momentum; e.g., the proton eigenstate in AdS/QCD with massless quarks has L = 0 and L = 1 light-front Fock components with equal probability. Higher Fock states with extra quark-anti quark pairs also arise. The soft-wall model also predicts the form of the nonperturbative effective coupling and its {beta}-function. The AdS/QCD model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method to systematically include QCD interaction terms. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. A method for computing the hadronization of quark and gluon jets at the amplitude level is outlined.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1002997
• Report Number(s): SLAC-PUB-14275; arXiv:1010.4962
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
BOUND STATE
CONDENSATES
CONFINEMENT
DIMENSIONS
EIGENSTATES
FIELD THEORIES
GLUONS
HADRONS
HAMILTONIANS
HOLOGRAPHY
LIGHT CONE
ORBITAL ANGULAR MOMENTUM
PHYSICS
PROBABILITY
PROTONS
Phenomenology-HEP
Theory-HEP
HEPPH
HEPTH
QUANTUM CHROMODYNAMICS
QUARKS
SCHROEDINGER EQUATION
SPIN