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The mystery behind the highest accuracy of antimatter measurement is still unsolved

Original title: antimatter measurement with the highest accuracy of two parts per trillion still cannot explain the biggest mystery

According to foreign media reports, at present, scientists have made the most accurate measurement of antimatter, with an accuracy of 2 parts per trillion. However, the results will only make the mystery of life and everything in the universe more complicated.

The latest measurement results show that the behavior characteristics of antimatter and matter are the same with quite high accuracy. So far, all measurements have failed to explain one of the biggest mysteries in Physics: If equal amounts of matter and antimatter were produced during the big bang, why is the universe mainly composed of matter today?

Our universe is based on the balance of opposites. For each type of 'normal particles' composed of matter, there is a conjugate antiparticle of the same mass, which generates opposite charges at the same time. Electrons have opposite antielectrons, or positrons; protons have antiprotons, and so on.

When matter and antimatter particles meet, they annihilate each other, leaving only the remaining energy. Physicists believe that the matter and antimatter produced by the big bang should be equal, and each of them ensures the common destruction of the other, making the early universe lose its life building component. Today, however, the universe is full of matter and gives birth to life on earth.

But there is a problem: we don't know any primitive antimatter produced by the big bang. If the behavior characteristics of antimatter and matter are the same, why can one survive the big bang while the other doesn't?

Stefan Ulmer, a physicist at the Japan Institute of physics and chemistry, said that one of the best ways to answer these questions is to measure the basic properties of matter and the conjugate properties of antimatter, and compare the results as accurately as possible. If there is a slight deviation between the properties of matter and the related antimatter properties, this may be the first important clue to the biggest mystery in physics. In 2017, scientists found some slight differences in the behavior of matter and antimatter, but the results are not statistically significant.

But if scientists want to manipulate antimatter, they have to work hard to make it, said Jeffrey hangst, a physicist at the University of Aarhus in Denmark and the author of the study. In recent years, some physicists have begun to study antihydrogen, or the antimatter form of hydrogen, because hydrogen is' one of the elements we know most about in the universe '. Making antihydrogen atoms involves mixing 90000 antiprotons and 3 million positrons to produce 50000 antihydrogen atoms. Scientists conducted experiments in a 28 cm long cylindrical tube and found that only 20 were trapped by magnets.

The latest study is published in the April 4 issue of the journal Nature. In 15000 antihydrogen atoms (more than 750 times in the experiment of mixing antiprotons and positrons), they studied the frequency of light emitted or absorbed by atoms when they transition from low energy level to high energy level.

The researchers' measurement results show that the energy level and optical absorption data of anti hydrogen atom are consistent with that of hydrogen atom, with an accuracy of 2 parts per trillion, which significantly improves the previous measurement accuracy.

Ulmer pointed out that it is very rare that the experimenters imagine that the accuracy has been increased by 100 times. He believed that if the hankerster team continued the research for 10-20 years, they would improve the accuracy of hydrogen spectrum by 1000 times.

For the spokesperson for the alpha collaboration at the European Center for Nuclear Research (CERN), the findings are a result of decades. He said: 'capturing and possessing antimatter is a major achievement. '

"20 years ago, people thought it couldn't happen, it was a masterpiece of experiment, and it was very difficult to do it," said hangster. '

Michael doser, a physicist at CERN who was not involved in the study, said: 'the latest results are impressive, and the number of atoms captured in this measurement (15000) is a great improvement on the record of the Hungarian team a few years ago. '

So, what is the most accurate measurement of antimatter? Unfortunately, there is not much room for us to explore. As we expected, hydrogen and antihydrogen atoms, matter and antimatter, their behavior characteristics are very similar. At present, we only know that they are the same when measured to a trillionth of an accuracy. However, urmer said that the accuracy of two parts per trillion does not rule out the possibility that the difference between the two types of substances of a certain substance will reach a greater accuracy, which will deviate from the measurement results.

As for hugster, he doesn't care why our physical world exists, because it has no antimatter - he calls it 'the elephant in the room'. Instead, he and his team want to focus on more accurate measurements, exploring the reaction of antimatter to gravity, whether it falls like normal matter, or does it fall?

He believes the mystery can be revealed by the end of 2018, when CERN will close for a two-year upgrade. He said: 'we have other ways to solve these problems. Let's wait and see.'