Higgs mechanism is to give the particles excited by gauge field mass, that is, without Higgs mechanism, the particles excited by gauge field have no mass (the reason why Pauli angered Yang Zhenning). The physics needed at this time is gauge field theory. To understand gauge field theory, we need to know what a field is and its quantization (refer to ETH-Institute for Theoretical Physics) and the basic knowledge of Lie algebra (there is a textbook on how to learn Lie algebra step by step). How important is group theory to theoretical physics? ) Symmetry breaks spontaneously. It is said that the symmetry of vacuum is less than that of excited state (slightly generalized), which is the GoldSi Tong theory. The physics needed at this time is a complex scalar field (including the interaction term). The required knowledge is the same as the gauge field theory. See chapter 7 of ETH- Institute of Theoretical Physics for details (go directly to see what you don't understand, and then write it down and read the handout from the beginning. )