Ah. Bougourzi et al., FROM QUANTUM AFFINE GROUPS TO THE EXACT DYNAMICAL CORRELATION-FUNCTION OF THE HEISENBERG-MODEL, International journal of modern physics b, 11(1-2), 1997, pp. 103-107
The exact form factors of the Heisenberg models XXX and XXZ have been
recently computed through the quantum affine symmetry of XXZ model in
the thermodynamic limit. We use them to derive an exact formula for th
e contribution of two spinons to the dynamical correlation function of
XXX model at zero temperature.