When we talk about what constitutes matter, the three fundamental particles immediately come to mind: electrons, protons and neutrons. It was once believed that these were the only particles that gave life to any matter. However, with scientific advances, it was realized that these “indivisible particles” could no longer be considered indivisible.
As far as we know, electrons, which orbit around the atomic nucleus, are the only particles that cannot be broken down into smaller particles. Protons and neutrons, which are together in the nucleus of an atom, can be broken down into even smaller particles. These particles are called Quarks.
As far as we know, there are at least six different species of quarks, discovered through experiments carried out in large particle accelerators. There are up quarks and down, strange, charm, bottom and top quarks.
The first two quarks mentioned form protons and neutrons. We can say that these particles are the most essential particles for the composition of the Universe.
The top quark was the last quark to be discovered. It was observed in 1995, through experiments carried out using the Tevatron, Fermilab's gigantic particle accelerator. In this accelerator, protons and antiprotons, with an energy of 0.9 TeV, that is, 9x1011 eV, collide in the center of two large particle detectors.
Very rarely does the collision produce a meson formed by a top quark and a top antiquark. This meson decays so quickly that it cannot be observed directly, however, its existence can be deduced from the products of the decay.
By Domitiano Marques
Graduated in Physics
Brazil School Team
