The Standard Model of the Universe

The standard model is a theory thatdisplays modern ideas about the initial base material for building the universe. This model describes how the matter is formed from its basic components, what forces of interaction exist between its components.

The essence of the standard model

In its structure, all elementary particles(nucleons), of which the atomic nucleus consists, as well as any heavy particles (hadrons), consist of even smaller simple particles, called fundamental ones.

Such primary elements of matter in the presenttime are considered quarks. The lightest and most common quarks are divided into upper (u) and lower (d). The proton consists of a combination of uud quarks, and a neutron - udd. The charge of the u-quark is equal to 2/3, while the d-quark has a negative charge, -1/3. If we calculate the sum of the charges of the quarks, then the proton and neutron charges turn out to be strictly equal to 1 and 0. This gives grounds to believe that the standard model absolutely adequately describes the reality.

There are several pairs of quarks that make up more exotic particles. So, the second pair consists of charmed (c) and strange (s) quarks, and the third pair is true (t) and beautiful (b).

Almost all the particles that could predict the standard model have already been discovered experimentally.

In addition to quarks, as a "buildingmaterial "are the so-called leptons. They also form three pairs of particles: an electron with an electron neutrino, a muon with a muon neutrino, a tau lepton with a tau lepton neutrino.

Quarks and leptons, according to scientists, arethe main building material on the basis of which the modern model of the Universe was created. They interact with each other with the help of carrier particles that transmit power pulses. There are four main types of such interaction:

- strong, thanks to which quarks are held inside the particles;

- Electromagnetic;

- weak, which leads to forms of decay;

- gravitational.

Strong color interaction carries particles called gluons, which lack mass and electric charge. Quantum chromodynamics studies this type of interaction.

Electromagnetic interaction is carried out by the exchange of massless photons - quanta of electromagnetic radiation.

Weak interaction occurs due to massive vector bosons, which are almost 90 times larger than protons.

Gravitational interaction ensures the exchange of gravitons, which do not have mass. However, it has not been possible to detect these particles experimentally yet.

The standard model considers the first three typesinteraction as three different manifestations of a single nature. Under the influence of high temperatures, the forces that act in the Universe are actually fused together, so that they can not be later discerned. The first, as scientists have found out, are the weak nuclear and electromagnetic interactions. As a result, it creates an electroweak interaction, which we can observe in modern laboratories during the operation of particle accelerators.

The theory of the universe says that in the period of itsappearance, in the first milliseconds after the Big Bang, the line between electromagnetic and nuclear forces was absent. And only after lowering the average temperature of the universe to 10 14 K, four types of interaction were able to separate and take a modern look. While the temperature was higher than this mark, only the fundamental forces of gravitational, strong and electroweak interaction acted.

The electroweak interaction is combined withstrong nuclear at a temperature of about 10 27 K, which is unattainable in modern laboratory conditions. However, even the Universe itself does not possess such energies, therefore it is not yet possible to confirm or deny this theory practically. But the theory, which describes the processes of combining interactions, allows us to give some predictions about the processes occurring at lower energy levels. And these forecasts are now confirmed experimentally.

Thus, the standard model offersthe theory of the structure of the universe, the matter of which consists of leptons and quarks, and the types of interaction between these particles are described in grand unification theories. The model is still incomplete, since it does not include gravitational interaction. With the further development of scientific knowledge and technologies, this model can be supplemented and developed, but at present it is the best that scientists could develop.