Explain antimatter from the perspective of modern physics

Roger Jones is a professor of physics and Dean of Lancaster University (England). This article is his explanation of antimatter and was first published in The Conversation.

We have heard a lot about antimatter but in the end, what is it and how does it apply in scientific practice?

Antimatter is one of the most interesting physical discoveries in the 20th century. Although the term has been mentioned by some novelists like Dan Brown, many people still don't really understand the reason. this theory. In fact, antimatter is growing and playing an important role in helping scientists study the mechanism of the universe.

What is antimatter?

Antimatter consists of antiparticles that, according to physicists, are "antimatter friends" identical to the particles that we know but have opposite charges , such as the same "couple". electron mass (negative charge) - positron (positive charge). When these particles (particles and antiparticles) come into contact with each other, they cancel each other out and their disappearance creates a light explosion.

The combination of particles and antiparticles can create explosions

These particles were first conjectured by British physicist Paul Dirac when he tried to combine two great ideas about modern physics in the early days: Relativity and quantum mechanics . Previously, there was a prediction that particles could have lower energy than when they were in a "rest" state (meaning there was no reaction) if they successfully combined these two theories, however , scientists at that time still couldn't explain it because the existence of negative energy sources was impossible.

However, the equations made Dirac believe that the particles actually contained a large amount of negative energy and that the previous scientists had yet to find out because they only studied "on the surface" without digging into it. Search. To break the traditional style, Dirac argues that all "normal" energy levels are formed by "normal" particles. However, when a particle "jumps" from a lower energy level to become a "normal" particle, it leaves a "hole" that to us seems to be a seed. counter-weird. That is the antimatter particle.

Although there are still doubts, examples of particle-antiparticle pairs have also been found early. For example, they are created when cosmic rays (Comic rays) hit the Earth's atmosphere or another evidence that energy during storms produces antiparticles of Positron. This antiparticle is also formed from some radioactive decay - the process used in Positron Emission Tomography (PET) scanners in many hospitals to produce accurate images of the body. people. In addition, experiments performed with the Large Hadron Collider (LHC) particle accelerator can also create particles and antiparticles.

Physicists argue that antimatter was created during thunderstorms

The mystery of matter and antimatter

Physics predicts that matter and antimatter must be created in nearly the same amount and this can be applied in the Big Bang, and the laws of physics apply to all. particles and antiparticles to ensure CP symmetry. However, the universe we know is capable of not following these rules because it is almost made of matter. Therefore, the disappearance of antiparticles is still mysterious.

In fact, there is not enough evidence to explain the difference between the amount of matter and antimatter in the universe despite the evidence (experiments) on some radioactive decay processes that do not create a equal amounts of particles and antiparticles. Therefore, many physicists (including myself) are still conducting experiments at the LHC (Large Hadron Collider), ATLAS, CMS, LHCb and some other researchers also conducting experiments on Neutrinos. at T2K in Japan to explain this "tough puzzle".

NASA scientists use telescopes to find evidence of antimatter

Other groups of physicists such as Alpha Collaboration at CERN have performed an experiment on lower energy levels to see if the properties of antiparticle are indeed reflections of corresponding matter particles. . The latest results show that an anti-hydrogen atom (made up of an anti-proton and an anti-electron or positron) does not carry an electrical charge (electrically neutral) with an accuracy of less than 1 parts per billion. electrons of electrons. By combining with other measurements, this result implies that the positron is electrically charged and has an equal magnitude of electrons with an error of less than one part per billion.

Although the above result confirms what is expected of antimatter, there are still many unexplained great mysteries, such as whether gravity influences antimatter as it affects material or not? If the symmetry rule is broken, the physics industry will need fundamental reforms and this will not only affect particle physics but also the understanding of gravity and relativity.

In fact, antimatter experiments are helping people access more interesting things about the basic operation of the universe and who is sure what we will find?

Author: Roger Jones