Why do we exist? This is perhaps the most profound question that may seem beyond elementary particle physics. But our new experiment at the Large hadron Collider at CERN has brought us closer to the answer. To understand why we exist, you first have to go 13.8 billion years ago, in the time of the Big Bang. This event is made equal to the amount of substance of which we consist, and antimatter.
It is believed that every particle has a partner of antimatter, which is almost identical but has the opposite charge. When a particle and its antiparticle meet, they annihilate — disappearing in a flash of light.
Where’s all the antimatter?
Why the universe we see consists entirely of matter, it is one of the greatest mysteries of modern physics. If ever there were an equal amount of antimatter, everything in the Universe would be annihilated. And now, a recently published study seems to have found a new source of asymmetry between matter and antimatter.
About antimatter was the first to speak Arthur Schuster in 1896, and then in 1928 Paul Dirac gave her a theoretical justification, and in 1932 Carl Anderson found it in the form of antielectrons, called positrons. Positrons are born in natural radioactive processes, e.g. the decay of potassium-40. This means that conventional banana (contains potassium) emit a positron every 75 minutes. He then annihilate with electrons in matter, producing light. Medical applications such as PET scanners also produce antimatter in a similar process.
The basic building blocks of matter composed of atoms are the elementary particles — the quarks and leptons. There are six types of quarks: top, bottom, strange, charmed, true and beautiful. Similarly, there are six leptons: electron, muon, Tau and three neutrinos. There is also antimatter copies of these twelve particles that differ only in their charge.
Particles of antimatter, in principle, should be a perfect mirror reflection of their normal companions. But experiments show that this is not always the case. Take, for example, the particles known as mesons, which consist of one quark and one antiquark. Neutral mesons have an amazing feature: they can spontaneously turn into its anti-meson, and Vice versa. In this process, the quark becomes an antiquark antiquark or quark turns into. However, experiments have shown that it may occur more frequently in one direction than in another — as a result, matter becomes greater over time than antimatter.
Third time’s the charm
Among the particles containing quarks, such asymmetry was found only in strange and beautiful quarks — and these discoveries were extremely important. The first observation of the asymmetry involving strange particles in 1964 allowed the theorists to predict the existence of six quarks — at a time when it was known that there are only three. The opening of the beautiful asymmetry of the particles in 2001 was the final confirmation of the mechanism that led to the picture of six quarks. Both discovery brought the Nobel prize.
And strange, and beautiful quarks carry a negative electrical charge. The only positively charged quark, which in theory should be able to form particles that can exhibit the asymmetry of matter and antimatter is enchanted. Theory suggests that he does, its effect should be negligible and hard to find.
But the LHCb experiment at the Large hadron Collider was able to observe this asymmetry in particles called D-mesons, which are composed of charmed quarks. This was made possible thanks to the unprecedented number of charmed particles produced in collisions at the LHC. The result shows that the probability that a statistical fluctuation is 50 billion.
If this asymmetry does not arise from the same mechanism that leads to the strange and beautiful asymmetries of the quarks, there is a space for new sources of asymmetry matter-anti-matter, which can add to the total of such asymmetry in the Universe. And this is important, as several famous cases of asymmetry can not explain why the Universe is so much matter. Single opening with charmed quarks is not enough to fill this problem, but it is an important piece of the puzzle in understanding the interaction between fundamental particles.
The following steps
This opening will be followed by a growing number of theoretical works that help in the interpretation of the result. But more importantly, it will identify further tests to better understand our inception — some of these tests already conducted.
In the coming decade the upgraded LHCb experiment will increase the sensitivity of such measurements. It will be complemented by the Belle II experiment in Japan, which only starts to work.
Antimatter is also the basis of several other experiments. Whole in which anti-atoms produced at the Antiproton decelerator of CERN, and they provide a number of experiments to conduct high-precision measurements. The AMS-2 experiment on Board the International space station, is in search of antimatter of cosmic origin. A number of current and future experiments will be devoted to the question of whether the asymmetry of matter-antimatter among neutrinos.
Although we still cannot fully solve the mystery of the asymmetry of matter and antimatter, our latest discovery opened the door to an era of precise measurements that can uncover even unknown phenomena. There is every reason to believe that one day physics will be able to explain why we’re even here.
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