Low-energy potential scattering in two and three dimensions
  Conditions are established for the existence of a scattering length and an effective range in the low-energy expansion of the S-wave phase-shift of a central potential in two and three dimensions. The behavior of the phase-shift as a function of the momentum is also derived for longer-range power-law potentials which do not fulfill these conditions. 
N. N. Khuri (Rockefeller), Andre Martin (CERN), Jean-Marc Richard   (Grenoble) and Tai Tsun Wu (Harvard)