ABSTRACT
Quantum scattering theory is concerned with transitions between states which have a continuous energy spectrum, i.e., which are unbound. The most common application of scattering theory in chemical physics is to collisions involving atoms, molecules and/or electrons. Such collisions can produce many possible results, ranging from elastic scattering to reaction and fragmentation. Scattering theory can also be used to describe collisions of atoms, molecules and/or electrons with solid surfaces and it also has application to many kinds of dynamical process in solids. These latter include collisions of conduction electrons in a metal with impurities or with particle surfaces, or collisions of collective wave motions such as phonons with impurities, or adsorbates. Scattering theory is also involved in describing the interaction of light with matter, including applications to elastic and inelastic light scattering, photoabsorption and emission. Additionally, there are many processes where continuum states of particles are coupled to continuum states of electromagnetic radiation, including photodissociation of molecules and photoemission from surfaces.
