Two-Body Problem: Scattering States

The experimental setup of atomic or nuclear scattering is an appropriate realization of the ideal setup depicted in Fig. 3.1. The beam is prepared by a particle accelerator in a state \(\Psi ^\textrm{in}\) . Then it is sent to a target, where the beam particles interact with the target particles. The outgoing particles reach a detecting array, where each detector \(D_k\) is devised to detect particles in a definite state \(\Psi _k^\textrm{out}\) . The experimental data are the set of counts at each detector, giving the particle’s probability of being in \(\Psi _k^\textrm{out}\) , expressed in terms of cross section.