A Remark on One-Dimensional Many-Body Problems with Point Interactions
  The integrability of one dimensional quantum mechanical many-body problems with general contact interactions is extensively studied. It is shown that besides the pure (repulsive or attractive) $\delta$-function interaction there is another singular point interactions which gives rise to a new one-parameter family of integrable quantum mechanical many-body systems. The bound states and scattering matrices are calculated for both bosonic and fermionic statistics. 
Sergio Albeverio, Ludwik Dabrowski and Shao-Ming Fei