The theoretical description of particles is based on quantum field theory. To describe electromagnetic interactions, quantum electrodynamics (QED) is used, weak and electromagnetic interactions are jointly described by the unified theory - the electroweak model (EFM), and the strong interaction - by quantum chromodynamics (QCD). QCD and EFM, jointly describing the strong, electromagnetic and weak interactions of quarks and leptons, form a theoretical scheme called the Standard Model.

Astrophysical and cosmological studies point to the existence of physics beyond the Standard Model. Thus, an observational fact is the baryon asymmetry of the Universe, while in the Standard Model the baryon number is constant. Another fact is the presence in space of the so-called latent mass, which is usually explained by the existence of dark matter, unknown to modern physics of nature. And finally, inexplicable in the framework of modern physics is the fact of the accelerated expansion of the Universe, which is usually associated with the so-called dark energy.

A separate issue is the so-called gauge hierarchy problem, which consists in the fact that the characteristic energy scales of strong (200 MeV) and electroweak (256 GeV) interactions are many orders of magnitude lower than the scale of the gravitational interaction (1019 GeV), as well as the assumed scale of the Grand Unification of interactions (1016 GeV ) and the scale associated with CP conservation in strong interactions (1014 GeV). Questions of the nature of such a hierarchy, the reasons for its stability and the presence of a large “desert” between two groups of scales are topical.

Another hierarchical problem is related to fermionic masses. In the Standard Model, all fermionic fields (leptons and quarks) form three generations. At the same time, the masses of generations differ many times, although the other properties of particles of different generations do not differ. The explanation of such a hierarchy is one of the problems of modern physics.

There are also theoretical difficulties in describing hadrons. In particular, to understand the nature of confinement, it is necessary to use non-perturbative methods of quantum chromodynamics.

During the twentieth century, many "theories of everything" have been proposed, but none of them have been able to pass experimental verification, or there are significant difficulties in organizing experimental verification for some of the candidates. The main problem of building a scientific "theory of everything" is that quantum mechanics and general relativity (GR) have different areas of application. Quantum mechanics is mainly used to describe the microcosm, while general relativity is applicable to the macrocosm. Special theory of relativity (SRT) describes phenomena at high speeds, and GRT is a generalization of the Newtonian theory of gravity, combining it with SRT and extending to the case of large distances and large masses. Direct combination of quantum mechanics and special theory of relativity in a single formalism (quantum relativistic field theory) leads to the problem of divergence - the absence of final results for experimentally verified quantities. To solve this problem, the idea of ​​renormalization of quantities is used. For some models, the renormalization mechanism allows one to build very well working theories, but the addition of gravity (that is, the inclusion in the theory of general relativity as a limiting case for small fields and large distances) leads to divergences that have not yet been removed. However, it does not at all follow that such a theory cannot be constructed.

The study of elementary particles.

The most comon of which are electrons, protons and neutrons making up normal matter. Also photons for light.

There are a host of short lived particles muons, pions , omegas,...

The Standard model describes the overall classification of the particle zoo.

Dear Pushkin Sergey Viktorovich

Thank you for your useful explanation.