Covariant light front perturbation theory and three-particle equations
A covariant version of light front perturbation theory is obtained as a limit of the covariant time-ordered perturbation theory developed recently by the author. The graphical rules for the covariant light front perturbation theory are essentially the same as Weinberg's infinite momentum frame rules; however, they involve a redefinition of the original Weinberg variables. The new definitions guarantee that the contributions of individual diagrams to the S matrix are invariant. A set of manifestly invariant three-particle integral equations is derived. These equations are obtained from a model field theory which describes the interaction of a charged scalar particle psi with a neutral scalar particle phi according to the virtual process psiarrow-right-leftpsi+phi. The solutions of the integral equations lead to amplitudes for phi+psi..-->..phi+psi and phi+psi..-->..2phi+psi which satisfy two- and three-particle unitarity. The integral equations are free of the spurious singularity in s, the square of the invariant c.m. energy, which has been an undesirable feature of earlier relativistic three-particle equations. This singularity is known to be responsible for spurious bound state solutions.
- Research Organization:
- Department of Physics and Astronomy, State University of New York at Buffalo, Buffalo, New York 14260
- OSTI ID:
- 6750145
- Journal Information:
- Phys. Rev. C; (United States), Vol. 35:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
THREE-BODY PROBLEM
PERTURBATION THEORY
BOUND STATE
FEYNMAN DIAGRAM
INTEGRAL EQUATIONS
LIGHT CONE
PROPAGATOR
QUANTUM FIELD THEORY
S MATRIX
SPACE-TIME
TIME DEPENDENCE
UNITARITY
DIAGRAMS
EQUATIONS
FIELD THEORIES
MANY-BODY PROBLEM
MATRICES
645400* - High Energy Physics- Field Theory