The Dynamical Correlation Function of the XXZ Model
arXiv:hep-th/9407062
Abstract
We perform a spectral decomposition of the dynamical correlation function of the spin XXZ model into an infinite sum of products of form factors. Beneath the four-particle threshold in momentum space the only non-zero contributions to this sum are the two-particle term and the trivial vacuum term. We calculate the two-particle term by making use of the integral expressions for form factors provided recently by the Kyoto school. We evaluate the necessary integrals by expanding to twelfth order in . We show plots of , for and at various values of the anisotropy parameter, and for fixed anisotropy at various around and .
20 pages (LaTeX), CRM-2198