R-matrix theory

R-matrix theory is a mathematical framework used primarily in quantum mechanics to analyze scattering processes, which occur when particles collide. It helps describe how incoming particles interact and scatter into different states after the collision. The "R" stands for the "resonance" matrix, which encodes information about the probabilities of various outcomes from these interactions. By modeling these processes, R-matrix theory provides insights into the underlying dynamics of particle behaviors, aiding in the understanding of complex systems in nuclear and atomic physics.