  We apply a semiclassical approach to express finite temperature dynamical
correlation functions of gapped spin models analytically. We show that the
approach of [A. Rapp, G. Zarand, Phys. Rev. B 74, 014433 (2006)] can also be
used for the S=1 antiferromagnetic Heisenberg chain, whose lineshape can be
measured experimentally. We generalize our calculations to O(N) quantum spin
models and the sine-Gordon model in one dimension, and show that in all these
models, the finite temperature decay of certain correlation functions is
characterized by the same universal semiclassical relaxation function.
