Quarks, the elementary particles that make up the protons and neutrons of the atomic nucleus, are fermions. And electrons, too. There are several types, although physicists like to talk more about ‘flavors’: above (up), below (down), charm (charm), strange (strange), top (top) and background (bottom). The most frequent in ordinary matter are the up and down quarksalthough the one that interests us the most in this article is the top quark for a very interesting reason: it is the heaviest elementary particle that we can find in nature.
An interesting note given that we are moving in the field of fermions: supersymmetry is a theoretical model of particle physics that proposes the existence of a hypothetical particle that is paired with each of the fundamental particles that we know. It seeks to explain the existing relationship between the bosonswhich have a spin with an integer value, and fermions, which have a half-integer spin. However, it is important that we do not overlook that it is a hypothetical theoretical framework that, therefore, has not yet been observed in nature. Not even experimentally.
CERN has investigated whether the top quark respects the special theory of relativity
The quantum mechanics and the special theory of relativity formulated by Albert Einstein constitute the heart of Standard Model of particle physics. Until now, this theory by the popular German physicist has stood the test of time undaunted, but scientists do not miss the slightest opportunity when it comes to putting it in trouble. And it is ideal because it is one of the most effective strategies when what is sought is to go beyond the solid walls of the Standard Model in the hope of develop new physics.
Some specific models of string theory propose that at very high energies special relativity will no longer be valid.
Lorentz symmetry lies at the very core of this model. Broadly speaking, this property justifies that the experimental results are independent of orientation and speed with which the experiment is carried out in the space-time continuum. It seems like a complicated concept, but if we think about it a little carefully, it is not so complicated. Be that as it may, what is really important is that so far all the experiments that physicists have carried out have supported Lorentz symmetry.
However, and here comes the most interesting part, some theories, such as specific models of string theory, propose that at very high energies special relativity will no longer be valid and experimental observations will depend on the orientation of the experiment in space. -time. If so, the Lorentz symmetry would be broken. On paper, it should be possible to identify this break in the energy level that physicists work with in the CMS particle detector from CERN (European Organization for Nuclear Research).
For months, CMS experiment researchers have meticulously analyzed the properties of the top quark pairs produced in the collisions at the LHC (Large Hadron Collider). And their result is very interesting: the production rate of top quark pairs remains constant even though the direction of the LHC’s proton beams and the average direction of the top quarks produced in the experiment change depending on the time of day due to the Earth’s spin on its axis. This means that there is no preferred direction in the space-time continuum capable of conditioning the production of top quarks. And, therefore, the Lorentz symmetry is still intact. And the special theory of relativity is still valid.
Image | CERN
More information | ScienceDirect