How did Yang and Mills use Lie groups to study the strong interaction?
In 1954, physicists Chen Ning Yang and Robert L. Mills developed a gauge theory that utilized Lie groups to describe subatomic interactions. By applying the mathematical framework of Lie groupsâwhich possess specific symmetry and continuity propertiesâthey sought to formulate a gauge-invariant theory for the strong interaction.123
Specifically, Yang and Mills used the group of gauge transformations to address the isospin of strongly interacting particles. Their work established a geometric structure where the physics of a quantum field remains unchanged under these group transformations. This approach was later foundational for quantum chromodynamics, which describes the strong force through the exchange of gluons. Unlike electromagnetism, the Yang-Mills framework allows force-carrier particles to interact with one another, a property that helps explain the confinement of quarks and the short-range nature of the strong force.214