The four-neutron experiment found evidence of the existence of a long-searched particle containing four neutrons.
Although all atoms except hydrogen are made up of protons and neutrons, physicists have been searching for particles of one, three or four neutrons for more than half a century. Experiments by a team of physicists at the University of Munich University of Technology (TUM) in the accelerator laboratory at the Corching Research Complex suggest that there may be a particle with four bound neutrons.
Although nuclear physicists acknowledge that there are no proton-only systems in the universe, they have been searching for particles of one, three, or four neutrons for more than 50 years.
If there is such a particle, parts of the theory of strong interactions should be reconsidered. In addition, a detailed study of these particles will help to better understand the properties of neutron stars.
“Strong contact is a force that holds the world at its center. Atoms heavier than hydrogen are unimaginable without it,” said Dr. Thomas Westerman, who led the experiments.
Everything now shows the fact that this type of particle was formed in one of the recent experiments carried out on the van de Graf tandem particle accelerator, which is currently inactive at the Corching Research Complex.
Long tetranuotron searches
Twenty years ago, a French research team published the measurements, which were described as the signature of the desired tetranuotron. Subsequent work on other groups, however, shows that the method used did not prove the presence of tetranuotrons.
In 2016, the team attempted to create a tetranuotron from helium-4 in Japan by bombarding it with a beam of radioactive helium-8 particles. This reaction should result in beryllium-8. In fact, they were able to detect four such atoms. Based on the results of the measurements, the researchers concluded that the tetranuotron is unrelated to each other and decomposes rapidly into four neutrons.
In their experiments, Westerman and his team detonated lithium-7 at speeds up to 12 percent faster than the speed of light. In addition to the tetranuotron, it is expected to produce carbon 10. In fact, physicists were able to find this species. Repeatedly confirmed the result.
The group’s measurements correspond to the carbon 10 signature and the associated 0.42 mega electronvolt (MeV) tetranuotron, which is expected at the first excitation. In terms of measurements, a tetranuotron is approximately as stable as a neutron. It decomposes with beta decay with a half-life of 450 seconds. “For us, this is the only reasonable physical interpretation of the measured values in all genres,” Drs. Thomas Westerman.
From its measurements, the team achieved more than 99.7 percent. Or 3 sigma sure. In physics, however, the existence of a particle is considered final only if it reaches a resolution of 5 sigma. So scientists are now eagerly awaiting independent approval.
Note: Thomas Westerman, Andreas Bergmeier, Roman Jernhauser, Dominic Cole and Mahmoud Mahkoub, Frontier Quaternary Neutron Indicators, 2021. Available November 26th. Letters of Physics b.
DOI: 10.1016 / j.physletb.2021.136799
The Meyer-Leibniz Laboratory is a collaboration between the University of Technology in Munich and the Ludwig-Maximilian University in Munich in collaboration with the van de Graf tandem accelerator. The facility was closed in 2020 for structural reasons. in the beginning. All five faculty are graduates or staff of the University of Munich University of Technology.