  We investigate a family of spin-S chain Hamiltonians recently introduced by
one of us. For S=1/2, it corresponds to the Haldane-Shastry model. For general
spin S, we find indication that the low-energy theory of these spin chains is
described by the SU(2)_k Wess-Zumino-Witten model with coupling k=2S. In
particular, we investigate the S=1 model whose ground state is given by a
Pfaffian for even number of sites N. We reconcile aspects of the spectrum of
the Hamiltonian for arbitrary N with trial states obtained by Schwinger
projection of two Haldane-Shastry chains.
