ASYMPTOTIC BETHE-ANSATZ RESULTS FOR A HUBBARD CHAIN WITH 1 SINH-HOPPING/

We investigate spin-1/2 electrons with local Hubbard interaction and v ariable range hopping amplitudes which decay like sinh(kappa)/sinh(kap pa tau). Using Sutherland's Asymptotic Bethe Ansatz we derive the gene ralized Lieb-Wu integral equations from the two-particle phase shift. For half-filling we obtain a closed expression for the ground state en ergy density. Due to the nesting property there is a metal-to-insulato r transition at U-c(kappa > 0) = 0(+). In the singular limit kappa = 0 the charge gap opens when the interaction strength equals the bandwid th, U-c(kappa = 0) = W.