  We discuss a 1D many-body model of distinguishable particles with local,
momentum dependent two-body interactions. We show that the restriction of this
model to fermions corresponds to the non-relativistic limit of the massive
Thirring model. This fermion model can be solved exactly by a mapping to the 1D
boson gas with inverse coupling constant. We provide evidence that this mapping
is the non-relativistic limit of the duality between the massive Thirring model
and the quantum sine-Gordon model. We also investigate the question if the
generalization of this model to distinguishable particles is exactly solvable
by the coordinate Bethe ansatz and find that this is not the case.
