The Standard Model of particle physics is a highly successful theoretical framework that describes the fundamental particles and their interactions. It has been extensively tested and confirmed by numerous experimental observations. However, the Standard Model does not directly predict the masses of the particles it describes. The masses of elementary particles, such as quarks, leptons, and gauge bosons, are experimentally measured quantities.
The Higgs mechanism, which is a key component of the Standard Model, provides a mechanism for particles to acquire mass. According to this mechanism, particles interact with the Higgs field, and their mass arises from this interaction. The strength of the interaction determines the particle's mass.
While the Standard Model explains the mechanism behind mass generation, it does not predict the specific masses of particles. The values of particle masses are free parameters in the theory, meaning they have to be determined experimentally. These measurements are typically done using particle accelerators and detectors, where the properties and behavior of particles are studied.
The inability of the Standard Model to predict particle masses is considered one of its limitations. It suggests that there may be deeper underlying principles or mechanisms yet to be discovered that determine the masses of particles. The quest for a more fundamental theory, such as a theory of quantum gravity or a unification of forces, aims to address these open questions and provide a more complete understanding of particle masses and other fundamental aspects of the universe.