Adiabatic Hyperspherical Representation for the Three-body Problem in   Two Dimensions
  We explore the three-body problem in two dimensions using the adiabatic hyperspherical representation. We develop the main equations in terms of democratic hyperangular coordinates and determine several symmetry properties and boundary conditions for both interacting and non-interacting solutions. From the analysis of the three-body effective potentials, we determine the threshold laws for low energy three-body recombination, collision-induced dissociation as well as inelastic atom-diatom collisions in two dimensions. Our results show that the hyperspherical representation can offer a simple and conceptually clear physical picture for three-body process in two dimensions which is also suitable for calculations using finite range two-body interactions supporting a number of bound states. 
J. P. D'Incao and B. D. Esry
quant-ph