The differential scattering cross-section is formally defined as a kinematic observable derived from Lorentz-invariant transition amplitudes and phase space factors within the framework of relativistic quantum field theory. The core theoretical mechanism establishes that this quantity depends solely on external four-momenta, encapsulating the ratio of the invariant amplitude squared ($|\mathcal{M}|^2$) to a flux factor defined by relative velocities in the center-of-mass frame. This formalism rigorously connects measurable interaction probabilities with fundamental dynamical parameters while isolating kinematic constraints via energy-conserving Dirac delta functions and solid angle integration.
The differential scattering cross-section is formally defined as a kinematic observable derived from Lorentz-invariant transition amplitudes and phase space factors within the framework of relativist…