High-loop calculations have long been a challenging problem in quantum field theory. Conventional Feynman diagram calculations generate large amounts of data and consume a lot of computational resources. Associate Researcher Qingjun Jin and Dr. Yi Li have greatly simplified the complexity of the calculations by combining the methods of unitarity cuts and separating ultraviolet divergences. They obtained the complete results of the five-loop anomalous dimension for the first time, which are in complete agreement with the first two orders calculated by the semi-classical method. The new calculation method greatly improves computational efficiency.

Both images are illustrations of the unitarity cut method.