Coupled-cluster expansions for the lattice O(3) sigma model.

Abstract

The coupled-cluster method with the eigenvalue equations truncated according to the continuum limit is applied to the Hamiltonian lattice O(3) {sigma} model. The long wavelength approximation of the vacuum wave function and mass gaps are calculated up to order 8. The results show general scaling behavior according to the full {beta} function. {copyright} {ital 1996 The American Physical Society.}