Mechanisms of mass generation for particles in models with an extended Higgs sector: review of theoretical and experimental results

The mechanisms of particle mass generation are discussed within the framework of modern models that generalize the Standard Model of electromagnetic, weak, and strong interactions (hereinafter referred to as generalized models). In generalized models, the structure of the Higgs sector becomes more complicated, resulting in additional Higgs particles. Theoretical works of a number of authors are analyzed and experimental data obtained recently, possibly related to the Higgs sector of generalized models, are presented. Spontaneous violation of gauge symmetry and a possible explanation of the phenomenon of transition to a negative value of the square of the mass of a scalar field, which is used in spontaneous violation, are briefly discussed. The appearance of nonzero mass values of gauge bosons, fermions, and Higgs particles is considered in the framework of the procedure of spontaneous violation of gauge symmetry. The generation of particle masses in generalized models is discussed. Recent data indicating the possible existence of several new scalar particles with masses from tens to hundreds of GeV are considered, which may confirm the more complex structure of the scalar sector of generalized models compared to the structure of the scalar sector of the Standard Model. The results presented in the review can be useful in planning and interpreting the results of experiments on the search for scalar particles, as well as in the development of theoretical generalized models.