A team of physicists from CERN – European Organization for Nuclear Research -, located in Switzerland, managed to achieve an important milestone in the study of antimatter.
The researchers not only developed a method to produce a significant amount of the substance in the particle accelerator, but also found a way to keep it stable and almost immobile for a long period of time.
This allowed the team to conduct many experiments with this intriguing material.
According to the Standard Model of particle physics, every particle has an “antiparticle” with properties and electrical charge exactly opposite to its own.
In this manner, electrons have positrons as antiparticles, quarks have antiquarks and muons have antimuons, for example.
Additionally, when the two “opposite twins” meet, they annihilate each other from existence and normally produce light in the process.
However, as antimatter has an extraordinarily fleeting nature – and usually disappears before anything can be done with it – scientists have been working on ways to generate and maintain this material in controlled and stable conditions for decades to study it.
According to Sophia Chen, from the Wired website, CERN physicists were able to produce antihydrogens in the particle accelerator – hydrogen atoms, the simplest and most abundant element in the Universe, but which, instead of presenting an electron of negative charge orbiting a positively charged nucleus, they have the opposite, a positron orbiting around a negatively charged nucleus.
To produce the antihydrogens, scientists mixed 3 million positrons with about 90,000 antiprotons and exposed these particles to temperatures close to absolute zero – the cold causes the antimatter to slow down and prevent it from colliding (and annihilating) it with the matter.
This combination resulted in the generation of only 30 atoms of antihydrogen, but physicists repeated the process until they obtained 500 of them, and then they managed to capture them in a “trap”, where the antiatoms were kept in a vacuum.
According to Sophia, as predicted by the Standard Model, matter and antimatter must always behave as if they were face to face in front of a mirror, which means that the behavior of one must perfectly mirror that of the other. However, there is a problem with that prediction.
When the Big Bang occurred more than 13 billion years ago, matter and antimatter should have been produced in equal quantities and, consequently, annihilated each other.
Therefore, there would not be enough matter for the formation of galaxies, stars, planets and so on. However, we know there is something wrong with that, as there is much more matter than antimatter in the cosmos.
In this way, the physicists behind the production of antimatter wanted to create the antihydrogen atoms just to examine their properties and try to find out if there were any differences from ordinary atoms.
The team applied laser pulses over the antiparticles – hoping to find something that wasn’t predicted by the Standard Model – and concluded that the antihydrogens behave in the same way as conventional hydrogen atoms, exactly as described by the Laws of Physics.
Physicists ended up failing to rewrite the Standard Model.
But in their search for answers, they found ways to produce and capture atoms of antimatter in significant quantities and keep them “frozen” for periods of up to 24 hours – when the normal thing is that they move at almost the speed of light and disappear in just 40 billionths of a second.
And these are important achievements that will allow many other studies and experiments on these elusive particles to be carried out.