Pade and K -matrix approximations to the O(2 N ) model for large N

Journal Article · Thu Feb 28 23:00:00 EST 1991 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.43.1710· OSTI ID:6044134

Willenbrock, S ^[1]

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1. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (US)

The Pade approximation and the {ital K} matrix are techniques for constructing perturbative amplitudes which satisfy two-body unitarity exactly. We apply these approximations to the Goldstone-boson scattering amplitude in a spontaneously broken O(2{ital N}) model, in the large-{ital N} limit, and compare with the exact amplitude (to leading order in 1/{ital N}). The ({ital r},{ital r}) Pade approximation reproduces the exact large-{ital N} amplitude for all {ital r}. The {ital K} matrix, at any finite order, yields an amplitude which is qualitatively similar to, but not identical to, the exact amplitude.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6044134
• Journal Information: Physical Review, D (Particles Fields); (USA), Journal Name: Physical Review, D (Particles Fields); (USA) Vol. 43:5; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

645203* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
BOSONS
ELEMENTARY PARTICLES
GOLDSTONE BOSONS
HIGGS BOSONS
K MATRIX
MANY-BODY PROBLEM
MATRICES
PADE APPROXIMATION
PERTURBATION THEORY
POSTULATED PARTICLES
S MATRIX
SCALAR FIELDS
SCATTERING AMPLITUDES
TWO-BODY PROBLEM
UNITARITY