Direct calculation of the boundary S matrix for the open heisenberg chain
M.T. Grisaru, Luca Mezincescu, Rafael I. Nepomechie
Abstract
Abstract: We calculate the boundary S matrix for the open antiferromagnetic spin 1/2 isotropic Heisenberg chain with boundary magnetic fields. Our approach, which starts from the model's Bethe Ansatz solution, is an extension of the Korepin-Andrei-Destri method. Our result agrees with the boundary S matrix for the boundary sine-Gordon model with \\beta^2 \\rightarrow 8\\pi and with ``fixed'' boundary conditions.