scatterings

Scatterings refers to processes in which particles or waves are deflected or redistributed after interacting with a target or medium. They are studied across physics to infer properties of matter and interactions, from subatomic particles to photons and neutrons.

Scatterings are typically categorized as elastic or inelastic. Elastic scattering conserves kinetic energy in the center-of-mass frame, while inelastic scattering transfers energy to internal degrees of freedom or produces new particles. Scattering can be coherent or incoherent and occurs at various angles and energies; forward and backward scattering are common regimes.

In experimental and theoretical contexts, the differential cross section dσ/dΩ quantifies the probability of scattering into a solid angle. The total cross section σ sums over all directions. Scattering theory uses amplitudes, phase shifts, and approximations such as the Born approximation; the optical theorem links forward scattering to the total cross section. Calculations rely on interaction potentials and target structure.

Classic examples include Rutherford scattering, which revealed nuclear structure; Compton scattering, which probes electron dynamics; X-ray and neutron scattering for material and crystal structures; and light scattering phenomena such as Rayleigh and Mie scattering in the atmosphere. Scattering techniques are central to fields including nuclear, particle, and condensed-matter physics, as well as chemistry and materials science.