For 10 points, name this process in which particles are deflected by collisions with other particles.
Faxen and Holtsmark introduced the partial-wave expansion of a quantity named for this process.Wheeler proposed and Heisenberg developed a matrix named for this process in which each element corresponds to a Feynman diagram. The square of the absolute value of its namesake amplitude equals the differential cross section. The deep inelastic type of this process helped with the discovery of quarks. A type of this process that is inversely proportional to the fourth power of wavelength is named for Rayleigh and explains why the sky appears blue. For 10 points, name this process in which particles are deflected by collisions with other particles. 
Faxen and Holtsmark introduced the partial-wave expansion of a quantity named for this process.
scattering [accept specific types] 