The centre-of-mass problem in continuum calculations of nuclear reaction cross sections

A method of elimination, from continuum calculations of nuclear reaction cross sections, of all spuriosities deriving from the centre-of-mass motion is proposed. It is shown that, with a simple modification of the treatment of the one-particle continuum in nuclear reaction theory of Barrett and Delsanto (Phys. Rev. C.; 10:101 (1974)), it is possible to tie the centre-of-mass to the origin. (author)