  Using a recently proposed solution for an open antiferromagnetic spin-1/2 XXZ
quantum spin chain with N (even) spins and two arbitrary boundary parameters at
roots of unity, we compute the boundary scattering amplitudes for one-hole
states. We also deduce the relations between the lattice boundary parameters
appearing in the spin-chain Hamiltonian and the IR (infrared) parameters that
appear in the boundary sine-Gordon S matrix.
