Eight years of sword, scientists first experimental verification of strange matter!

《Nature》:八年磨一剑,科学家首次实验验证奇异物质!
FIG Abstract Art π meson irradiation of a laser beam of a helium atom. From Thorsten Naeser, Dennis Luck ,, MPQ

refers to a singular common atom or atoms is replaced by a plurality of components strange particles (e.g., particles of antimatter) atoms. Based on the world\’s most accurate atomic clock timer technology for the detection of these atoms can look for any minor differences between the nature of their properties and model predictions, thus opening a window-based physics. It stems from the fact that the interest in exotic atoms that they often help the most basic physics experimental strategies: changing a single parameter or other components in complex systems, in order to observe its effect. In fact, this is not so simple as it seems. The particles may have a different quality or different charge, different and may interact with the surrounding environment in other subtle ways, but these tend to increase the value of the subtleties singular atoms. More and more scientists investigate fundamental properties of nature by studying these atoms improvements in technology as exotic atomic research required. An important feature of the underlying physical singular atom as a probe is that they are bound system having a plurality of states within the energy (the energy required to pull the composition). Thus, the transition between these states may be performed by laser spectroscopy study, laser spectroscopy physics toolbox most accurate measurement tool. Research atomic transition, in particular the study of hydrogen atom transition is an ongoing work of more than two centuries. For example, it inspired the Niels Bohr model of the atom in the early seminal twentieth century, and promote the development of many of quantum mechanics. In 1947, Cecil Powell and his colleagues found that the π mesons, but in 1935, Hideki Yukawa predicted the existence of it for the first time π mesons. They belong to the family of subatomic particles is called meson, meson strong force is transmitted between the nuclei, neutrons and protons. Although having the same proton charges repel each other strongly, but strong nuclear force them together form nuclei. Without this power, our world would not exist. Mesons with protons and neutrons are fundamentally different, proton and neutron consists of three quarks, and mesons only two quarks. is a short-lived π meson particles, having a positively charged, negatively charged and neutral other forms, the nucleus is determinedAn important class of particle stability and decay. In 1964, then in some experiments, it has been predicted the existence of π mesons helium atoms theoretically. However, it is considered difficult to verify this prediction experimentally. Typically, in an atom, the very short-lived π atoms decay faster. However, π meson helium, which is conserved in a sense, it is a thousand times the life of the other atoms. After eight years of continuous research, a senior physicist Masaki Hori from the Max Planck Institute for Quantum Optics in Germany, led the team successfully completed a challenging experiment: in the helium atom, they are in with a particular quantum π meson state of an electronic substituted synthesized π4He +, π- and stimulate occupied π4He + transition track (n, l) = (17,16) (17,15 at the resonant frequency of the near-infrared gigahertz 183760 ). Laser-induced electromagnetic tandem process, in order to absorb π- nuclei and undergo fission end. To detect neutrons, protons and deuterons indicating the presence of fragments generated by laser-induced resonance, the first time that such a long-lived \”[pi] meson helium\” exists atoms. This work makes it possible to study meson quantum optics experimental techniques. The study \”Laser spectroscopy of pionic helium atoms\” was published on Nature. 《Nature》:八年磨一剑,科学家首次实验验证奇异物质! Researchers use negatively charged π meson 590MeV annular cyclotron provided with a magnet to focus them on a target comprising superfluid helium, the helium atom π meson prepared. In the experiment, the helium is cooled to a low temperature target of about 2K, so that some of the π meson π meson helium is trapped in the weakly bound state, wherein π meson sufficiently far from the nucleus, the remaining electrons can be shielded (FIG. 1). Therefore, exotic atoms produced retains the nanosecond life, this life is enough to make atomic laser pulses excite strange newborn.

《Nature》:八年磨一剑,科学家首次实验验证奇异物质!
FIG. 1 π meson how to make and excited helium. Hori et emission bunch negatively charged subatomic particles to liquid helium, called π meson. When the π meson impact helium atoms, which may be a hit electrons, higher energy level and replace it around the track in a helium nucleus (two protons and two neutrons), forming a singular atom, helium called π meson . OF emitting laser light to these exotic atoms, to observe the πMeson transition to a low energy level of the track, this process triggers excess electron injection. This accelerates the injection π meson absorption nuclei (not shown), eventually split nuclei.

Next, in order to confirm that these atoms have actually been created and how they Laser light absorption and the light resonance, the researchers emit different frequencies to the target and to find π meson atoms differ in their body examples for transition between quantum levels. After repeated tests of different laser frequencies, they can identify a particular hop. It is predicted that this transition will result in the absorption of helium nucleus π meson, helium nuclei then split into a proton, a neutron, and a composite particle composed of protons and neutrons. The researchers used a series of particle detectors to detect these fragments, thus confirming the π mesons indeed transition has occurred. π meson transition by removing large \”background\” signal from the experimental data to detect a carefully; π meson helium background and this short-lived fission products obtained relevant state, or π meson beam is generated by itself. This makes transitions only three hour π meson signals helium atoms, or estimated singular atoms per billion three generated signals. Despite the very low amounts, but laser-induced transitions of the signal can still be clearly detected, and may be an absolute accuracy of approximately 5 to determine the occurrence of significant digits of the laser transition frequency (and the frequency variation corresponding to the transition energy).

《Nature》:八年磨一剑,科学家首次实验验证奇异物质!
Experimental apparatus for generating and detecting a proton π meson helium atoms. π meson enters from the right, the laser beam enters from the left. Masaki Hori

\”laser spectroscopy meson containing exotic atoms can be used to accurately determine the quality and other properties of the composition mesons, and may involve the Sony meson to be limiting.\” Dr. Masaki Hori in said in an interview: \”for meson we used in the study, that is one of the lightest meson, we may eventually be able to precision higher than one hundred million determine its quality.\” \”it\’s reached so far than 100 times higher precision, and will allow an accurate comparison with the standard model predictions. \”for eight years, the team is committed to this challenging groundbreaking experiment, the experiment will be possible to build a new field of study. It was a scientific marathon, by the Max Planck Institute for Quantum Optics, Swiss Paul Scherrer Institute (PInternational cooperation between SI) and the European particle physics laboratory, CERN contributed. Experiments using the world\’s most powerful source of π mesons is located in the PSI. Due to the experimental risk of failure is very high, a lot of failures encountered during the experiment, the team got the long-term support PSI and the Max Planck Society (MPG) is. PSI provides a π meson beam time, CERN\’s technology groups provide an important part of equipment, MPG provides a favorable environment for long-term research. The project is funded by the European Research Council (ERC). Next, the researchers aim is to improve the recognition accuracy of transition and search for other transitions, in order to use them to measure π mesons quality and test the Standard Model. \”This success is a quantum optical methods research π mesons opened up a whole new way,\” Dr. Hori said happily. Reference Source: https: //www.mpq.mpg.de/en/2020-05-pionic-heliumhttp: //www.sci-news.com/physics/pionic-helium-08423.htmlhttps: //www.nature .com / articles / s41586-020-2240-xhttps: //www.nature.com/articles/d41586-020-01250-7

相关新闻