A recent study has reviewed the concept of analytic coupling in Quantum Chromodynamics (QCD), a fundamental theory describing the strong interaction between quarks and gluons. This review primarily builds upon previous results, offering an updated perspective on how the QCD coupling constant behaves across different energy scales, especially in the low-energy region where perturbative methods are not applicable. Understanding this coupling is crucial for describing phenomena such as quark confinement and hadron formation.

The practical application of this review has been demonstrated in the pion-photon transition form factor. This form factor is an experimentally accessible quantity that provides information about the internal structure of the pion, a subatomic particle composed of a quark and an antiquark. By applying the analytic QCD coupling, researchers can obtain more precise theoretical predictions for this form factor, enabling a more rigorous comparison with experimental data and, ultimately, validating or refining our understanding of the strong interaction.

This type of analysis is fundamental for advancing particle physics, as QCD is one of the four fundamental forces of nature. Improving the description of the strong coupling, particularly in the non-perturbative regime, is essential for resolving open problems like the origin of hadron mass and the dynamics of confined quarks. The ability to apply these models to specific processes such as the pion-photon form factor underscores the relevance of these theoretical investigations for interpreting high-energy experiments.