Light-Front-Quantized QCD in Light-Cone Gauge

Technical Report · Thu Nov 30 04:00:00 EST 2000

DOI:https://doi.org/10.2172/784789· OSTI ID:784789

Brodsky, Stanley J ^[1]

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1. SLAC

The light-front (LF) quantization of QCD in light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. We present a systematic study of LF-quantized gauge theory following the Dirac method and construct the Dyson-Wick S-matrix expansion based on LF-time-ordered products. The gauge field is shown to satisfy the Lorentz condition as an operator equation as well as the light-cone gauge condition. Its propagator is found to be transverse with respect to both its four-momentum and the gauge direction. The propagator of the dynamical + part of the free fermionic field is shown to be causal and to not contain instantaneous terms. The interaction Hamiltonian of QCD can be expressed in a form resembling that of covariant theory, except for additional instantaneous interactions which can be treated systematically. The renormalization factors are shown to be scalars and we find Z1 = Z3 at one loop order. The running coupling constant and QCD {beta} function are also computed in the noncovariant light-cone gauge. Some comments on the relationship of our LF framework to the analytic effective charge and renormalization scheme defined by the pinch technique are made. LF quantization thus provides a consistent formulation of gauge theory, despite the fact that the hyperplanes x{sup {+-}} = 0 used to impose boundary conditions constitute characteristic surfaces of a hyperbolic partial differential equation.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 784789
• Report Number(s): SLAC-PUB-8711
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOUNDARY CONDITIONS
COUPLING CONSTANTS
DEGREES OF FREEDOM
EFFECTIVE CHARGE
EXCLUSIVE INTERACTIONS
INCLUSIVE INTERACTIONS
MOMENTUM TRANSFER
PARTIAL DIFFERENTIAL EQUATIONS
QUANTUM CHROMODYNAMICS
S MATRIX
UNIFIED GAUGE MODELS