Differential cross-sections are a key concept in the field of particle physics and quantum mechanics. They are used to describe the probability of a particle scattering or interacting with another particle at a particular angle and energy. The differential cross-section is a measure of how likely a particular scattering event is to occur, and it can provide valuable information about the underlying interactions between particles. By studying differential cross-sections, researchers can gain insight into the fundamental forces and particles that make up the universe.