Higher Energies, Myriad of Particles: Their Classifications and Their Symmetries

With the emergence of a myriad of high energy particles which travel with speeds comparable to that of the speed of light, and for a proper description of their underlying dynamics in high energy processes, it became necessary to consider these particles live in a four dimensional pseudo-Euclidean space, referred to as Minkowski spacetime. As really imposed by nature at high energies, it has become essential as well, not only provide a classification scheme for them, based on symmetry principles, but also to “search” for the few fundamental particles as the building blocs that make up the myriad of high-energy particles created, which have been referred to as the fundamental particles of the standard model. In this chapter we learn (1) how such a spacetime description, unifying space and time, naturally arises, and gives rise to special relativity, (2) about the equivalence of matter and energy, (3) about the fundamental particles of the standard model, including the Higgs particle, (4) the basic aspects of particle symmetries and particle classifications, (5) the nature of the three basic interactions in nature at different energy scales, with the exception of gravitation which will be dealt with in Chap. 4 .