CHAPTER 2: Quantum Theory of Atom–Atom Elastic Scattering

This chapter is concerned with the quantum theory of atom–atom collisions. It introduces the concepts of orbital angular momentum, the partial wave expansion and phase shifts. The differences between the classical and quantum treatment of the problem are illustrated using the examples of Ne–Ne scattering. Cross sections calculated using classical and quantum mechanics are contrasted and compared. Calculated cross sections demonstrating glory and rainbow scattering are presented and the concepts of S and T matrices are introduced. The scattering of identical particles is also discussed. An example of a shape resonance is also presented.