The contour deformation method in momentum space, applied to subatomic physics

A generalized contour deformation method (CDM), which combines complex rotation and translation in momentum space, is discussed. CDM gives accurate calculation of two-body spectral structures: bound, antibound, resonant and continuum states forming a Berggren basis. It provides a basis for full off-shell t-matrix calculations both for real and complex input energies. Results for both spectral structures and scattering amplitudes compare perfectly well with exact values for the analytically solvable separable non-local Yamaguchi potential as a testcase. Accurate calculation of antibound states in the Malfliet-Tjon and the realistic CD-Bonn nucleon-nucleon potential are presented. Calculation of antibound states in the CD-Bonn potential are not known to have been given elsewhere.