Reggeization

Reggeization is a concept in theoretical physics, particularly in quantum field theory and particle physics, that describes how the scattering amplitudes of certain particles can be represented as a sum over contributions from "Regge poles." These poles correspond to particles that lie on Regge trajectories, which are relationships between the spin and mass (or energy squared) of particles. The idea was developed by Tullio Regge.

In essence, reggeization provides a way to organize and understand the behavior of scattering amplitudes at high energies. Instead of summing over all possible intermediate particles in a complex Feynman diagram expansion, reggeization suggests that at high energies, the dominant contributions come from the exchange of these Regge poles. These poles are not necessarily single, stable particles but can represent families of particles with the same quantum numbers but different spins, arranged along a Regge trajectory.

The process of reggeization applies to theories with certain symmetries, such as theories with massless particles or theories that exhibit an approximate symmetry. It is a powerful tool for simplifying calculations and provides insights into the underlying structure of scattering processes. The concept has been particularly influential in the study of strongly interacting particles, like hadrons, where it helped explain observed patterns in their scattering behavior. Regge theory and reggeization have also found applications in understanding the behavior of black holes and in certain areas of condensed matter physics.