Last Tuesday (2), the European Organization for Nuclear Research (CERN) announced the discovery of 59 new particles with the use of the Large Hadron Collider (LHC) in Geneva, Switzerland, four of them totally unpublished since the beginning of studies in the area in 2009. Some were already expected according to established theories, but others represent real surprises for the world scientific community.
From the LHC, researchers are able to explore properties of matter at the shortest distances and at the highest energies probed in the laboratory, thus enabling greater depth of the Standard Model of Particle Physics, a theory that describes forces and elements that constitute all the bodies in the Universe.
In fact, it was through the machine that the Higgs Boson, or “God particle”, the last missing piece of the hypothesis, came to light, guaranteeing the 2013 Nobel Prize in Physics to the British Peter Higgs and the Belgian François Englert. In short, it is the physical manifestation of the interaction of bosons, particles associated with forces (with the exception of photons) that produce spontaneous symmetry breaks in high energy regimes.
Despite all the achievements, the Standard Model of Particle Physics is far from being fully understood, since the detailed description of the force that holds the atomic nucleus together (formed by protons and neutrons, composed of three quarks) and its fundamental action on everything that exists is a scenario that has not yet been reached even by the most powerful equipment on Earth.
If that force disappeared for a second, the matter would disintegrate into a soup of loose quarks – a state that, it is assumed, existed for an instant in the beginning of time.
This property was called quantum chromodynamics, which explains how quarks interact through the exchange of other particles called gluons – analogues of the photon, particle of light and carrier of the electromagnetic force. The strength generated in this case is fundamentally different from that of his best known “sister”.
The more the quarks separate, the stronger the interaction becomes, something that keeps them irreparably attached to hadrons, particles made up of two or more quarks, generating protons and neutrons.
That is, arrested until they pass through CERN and reach absurd speeds, thus revealing themselves in the eyes of scientists. However, it is more complicated than it looks.
Test after test
Experts to date have not encountered a solitary quark, and the calculations necessary to detail a simple process in electromagnetism become highly complex in quantum chromodynamics. In addition, antiparticles, foreseen in the Standard Model of Particle Physics, end up appearing before quarks are extracted, thus creating a pair and slowing the evolution of research. Several experiments ended at the same point, also preventing even assumptions about which combinations of quarks would be viable and which would not.
Pairs of quarks and antiquarks (mesons), trios of quarks (baryons), trios of antiquarks (antibárions) and groups formed by two quarks and two antiquarks (tetraquarks) or four quarks and an antiquark (pentaquarks) have been combinatorial hypotheses proposed by scientists since the discovery of quarks, several proven over the years. Surprisingly, in addition to the consolidation of others with the recent CERN announcement, unexpected things have joined the list of analyzes.
Among the 59 new hadrons – possible combinations – found, four unpublished tetraquarks gave an “oizinho” to humanity, whose most striking difference is the presence, except for one, of pairs of heavy quarks called charm (charm, in free translation) and bottom (essence), thus evidencing some preferences of nature.
According to the researchers at the head of the ad, what is most striking is precisely the lack of explanation for the existence of these hadrons. For example, why are there no matching particles with strange quarks and they all contain a similar pair?
Anyway, such facts bring evidence of the existence of a physics beyond the standard model, notably inconsistent with current cosmological theories that describe the formation of the Universe.
Other particles could, in theory, fill the gaps in contemporary scientific knowledge. However, because they are hidden in the background of interactions, they are now beyond the reach of our full understanding.
That is, with each step taken, like the one recently announced, we are closer to the accurate description of the essential properties of matter – and to other perspectives of our existence in this blue point lost in space.