Particle Physics is the area of Physics that studies the elementary particles that make up matter, in addition to the radiation they emit and the interaction between them. Elementary particles are so called because they are indivisible and form all other particles found in nature.
The first researches related to isolated particles were done by the Greeks. The first article was formulated by Thales of Miletus, who addressed electricity as a theme. The second article was formulated by Democritus and stated that all matter could be divided until reaching its most fundamental and indivisible part, which introduced the idea of the atom.
For a long time, it was believed that elementary particles were photons, protons, neutrons and electrons. Until 1932, it was believed that these four particles formed all the matter that constituted nature.
Between 1932 and 1947, several new particles were discovered. Among them, the neutrino, in 1933, by the Italian Enrico Fermi.
A new method for detecting particles was created in 1933. It was based on the process of photographic emulsions, which are light-sensitive mixtures. Since then, other particles have been discovered, the first being the
muon and, later, the pion, in 1947, after the evolution of this method.The evolution in this area of research took place in such a way that by 1967, with the creation of particle accelerators, a set of more than two hundred particles had already been identified. The question now would be how to organize them, grouping them in order to reduce this amount.
Thus, the first step was to identify common characteristics between them, their regularities and symmetries, in an attempt to find common origins. The research carried out led researchers Murray Gell-Mann and Georg Zweig to conclude that many of the particles discovered that were considered elementary, such as protons and neutrons, were formed by other even smaller particles, that is, they were not elementary. These studies allowed a division and classification of several elementary particles into groups that considered their characteristics in common.
By Mariane Mendes
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/fisica/fisica-particulas-estudo-das-particulas-elementares.htm