Complex scaling method for two-particle equations in the momentum representation and resonance states

The complex scaling method is applied to the non-relativistic and relativistic two-particle equations in the momentum representation for resonance sates finding. The comparison of the resonance states spectra obtained in the momentum representation with the similar results obtained in the coordinate representation for the Schrödinger equation and in the relativistic configurational representation for the two-particle relativistic equations is carried out. A good agreement of the results obtained in different representations is shown.