  Correlation functions of primary fields in the Wess-Zumino-Novikov-Witten
(WZNW) model are known to satisfy a system of Knizhnik-Zamolodchikov (KZ)
equations, which involve constants of motion of the exactly-solvable Gaudin
magnet. We modify the KZ equations by replacing these Gaudin operators with
constants of motion of the closely-related Richardson pairing Hamiltonian and
reconstruct a deformed WZNW model, whose correlators satisfy these equations.
This modified theory, dubbed here the boundary WZNW model, contains a term that
breaks translational symmetry and therefore represents a generalized boundary
operator. The corresponding correlators of the boundary WZNW model are
calculated and are shown to acquire exponential prefactors, in contrast to the
bulk WZNW theories. The solution also establishes a connection between
correlation functions of the WZNW model and the spectrum of the reduced pairing
Hamiltonian.
