Underground Experiment Shows Sterile Neutrino A New Type Of Fundamental Particle Associated With Dark Matter

Several experiments from the 1990s studying neutrinos found something really strange: there were too many particles appearing in the detectors. In particle physics, even small deviations from the expected experimental results have excited scientists. Now, a new experiment conducted deep underground, more than two kilometers below the mountains of Russia’s Caucasus, confirms the previously observed anomaly, pointing to a new, as yet unconfirmed elementary particle called a “sterile neutrino.” Either that or our physique is flawed, so these results are incredibly important regardless of the outcome.

Sterile neutrinos deep underground

Neutrinos are nature’s most abundant particles, perhaps second only to photons, the particles of light. You can not notice them, but they are everywhere. In fact, every second, about one trillion neutrinos pass through your hand. Most of them come from the sun, while others are created in the upper atmosphere when gases are hit by cosmic rays from supernovae and other events in space. There are three known types, or flavors, of neutrinos: electron, muon and neutrinos. But many scientists believe that there is a fourth taste that remains in the shadows, waiting for the place it deserves with its family of particles. Experimental so-called sterile neutrinos, if any, could help solve many mysteries in physics, such as why neutrinos have mass when, in theory, they should be as massless as photons. Sterile neutrinos – so named because they are supposed to interact with other particles solely through gravity, while the other three flavors also do so through weak force – may also explain the nature of dark matter, the invisible and intangible matter that represents 85 % all matter in the universe, although we cannot measure it directly. Located deep underground in the Baksan Neutron Observatory in the Caucasus Mountains in Russia, the integrated two-gallon target, on the left, contains an inner and outer gallium tank, which is irradiated by a neutron source. Credit: AA Shikhin Researchers linked to the Baksan Experiment on Sterile Transitions (BEST), which includes U.S. researchers from the Los Alamos National Laboratory, used irradiated chromium disks 51 (a synthetic chromium radioisotope) and a powerful neutrino source for neutrino electrons. and the outer parts of a gallium tank. As a result of this reaction, the experiment produced the isotope germanium 71. This was perfectly expected, but what was abnormal was that the production rate was 20-24% lower than the theory suggested. The methodology of the experiment is believed to be flawless and, in addition, the deviation is in the same field as that recorded from other previous experiments. “The results are very exciting,” said Steve Elliott, chief analyst at one of the data analysis teams and a member of the Los Alamos Physics Division. “This certainly confirms the anomaly we have seen in previous experiments. But what this means is not obvious. There are now conflicting results regarding sterile neutrinos. “If the results indicate that fundamental nuclear or atomic physics is misunderstood, it would also be very interesting.” One of the previous experiments with similar results was the forerunner of BEST, a solar neutrino experiment from the 1980s called the Soviet-American Gallium Experiment (SAGE), which also used gallium and a high-intensity neutrino source. Both BEST and SAGE were performed thousands of meters below the entrance of a tunnel at the Baksan Observatory, located in the gorge of the Baksan River in the Caucasus Mountains of Russia. Neutrinos detectors are generally buried deep underground to protect them from interference from cosmic rays and other radiation that would wreak havoc on the experimenter if the detectors were exposed to the surface. A next-generation neutrino detector called the Deep Underground Neutrino Experiment, or DUNE, is currently being built 48 miles (30 miles) below ground at the Fermi National Accelerator Laboratory in Batavia, Illinois. When completed, it will be able to launch neutrino beams through the Earth’s mantle.

Did we lose dark matter because our understanding of physics is wrong?

There are many reasons why physicists love neutrinos. They provide a direct link between us and the sun’s core, allowing scientists to look through nuclear fusion processes without having to place probes in space. But perhaps the most fascinating thing about neutrinos is that they oscillate between flavors, like a chameleon that changes color in response to its environment. A particle that starts as an electron neutrino, for example, can be converted to a tau or muon neutrino and vice versa. Gaps in the timing of these oscillations recorded by the experiment in Russia, and others like them before, suggest that there is a fourth taste we are missing. This hypothetical particle may also well be an important component of dark matter. But this does not mean that a fourth type of elementary particle is the only explanation. The results of the experiment also raise the interesting possibility that our current theoretical framework describing neutrinos is defective. It would not be bad news at all. Science is an ongoing work in which the status quo is always accompanied by new, compelling evidence. In the process, the institution of science becomes stronger and more credible, as well as better equipped to answer increasingly complex questions about nature. The findings appeared in Physical Review Letters.

title: “Underground Experiment Shows Sterile Neutrino A New Type Of Fundamental Particle Associated With Dark Matter " ShowToc: true date: “2022-11-07” author: “Marjorie Rothfuss”

Several experiments from the 1990s studying neutrinos found something really strange: there were too many particles appearing in the detectors. In particle physics, even small deviations from the expected experimental results have excited scientists. Now, a new experiment conducted deep underground, more than two kilometers below the mountains of Russia’s Caucasus, confirms the previously observed anomaly, pointing to a new, as yet unconfirmed elementary particle called a “sterile neutrino.” Either that or our physique is flawed, so these results are incredibly important regardless of the outcome.

Sterile neutrinos deep underground

Neutrinos are nature’s most abundant particles, perhaps second only to photons, the particles of light. You can not notice them, but they are everywhere. In fact, every second, about one trillion neutrinos pass through your hand. Most of them come from the sun, while others are created in the upper atmosphere when gases are hit by cosmic rays from supernovae and other events in space. There are three known types, or flavors, of neutrinos: electron, muon and neutrinos. But many scientists believe that there is a fourth taste that remains in the shadows, waiting for the place it deserves with its family of particles. Experimental so-called sterile neutrinos, if any, could help solve many mysteries in physics, such as why neutrinos have mass when, in theory, they should be as massless as photons. Sterile neutrinos – so named because they are supposed to interact with other particles solely through gravity, while the other three flavors also do so through weak force – may also explain the nature of dark matter, the invisible and intangible matter that represents 85 % all matter in the universe, although we cannot measure it directly. Located deep underground in the Baksan Neutron Observatory in the Caucasus Mountains in Russia, the integrated two-gallon target, on the left, contains an inner and outer gallium tank, which is irradiated by a neutron source. Credit: AA Shikhin Researchers linked to the Baksan Experiment on Sterile Transitions (BEST), which includes U.S. researchers from the Los Alamos National Laboratory, used irradiated chromium disks 51 (a synthetic chromium radioisotope) and a powerful neutrino source for neutrino electrons. and the outer parts of a gallium tank. As a result of this reaction, the experiment produced the isotope germanium 71. This was perfectly expected, but what was abnormal was that the production rate was 20-24% lower than the theory suggested. The methodology of the experiment is believed to be flawless and, in addition, the deviation is in the same field as that recorded from other previous experiments. “The results are very exciting,” said Steve Elliott, chief analyst at one of the data analysis teams and a member of the Los Alamos Physics Division. “This certainly confirms the anomaly we have seen in previous experiments. But what this means is not obvious. There are now conflicting results regarding sterile neutrinos. “If the results indicate that fundamental nuclear or atomic physics is misunderstood, it would also be very interesting.” One of the previous experiments with similar results was the forerunner of BEST, a solar neutrino experiment from the 1980s called the Soviet-American Gallium Experiment (SAGE), which also used gallium and a high-intensity neutrino source. Both BEST and SAGE were performed thousands of meters below the entrance of a tunnel at the Baksan Observatory, located in the gorge of the Baksan River in the Caucasus Mountains of Russia. Neutrinos detectors are generally buried deep underground to protect them from interference from cosmic rays and other radiation that would wreak havoc on the experimenter if the detectors were exposed to the surface. A next-generation neutrino detector called the Deep Underground Neutrino Experiment, or DUNE, is currently being built 48 miles (30 miles) below ground at the Fermi National Accelerator Laboratory in Batavia, Illinois. When completed, it will be able to launch neutrino beams through the Earth’s mantle.

Did we lose dark matter because our understanding of physics is wrong?

There are many reasons why physicists love neutrinos. They provide a direct link between us and the sun’s core, allowing scientists to look through nuclear fusion processes without having to place probes in space. But perhaps the most fascinating thing about neutrinos is that they oscillate between flavors, like a chameleon that changes color in response to its environment. A particle that starts as an electron neutrino, for example, can be converted to a tau or muon neutrino and vice versa. Gaps in the timing of these oscillations recorded by the experiment in Russia, and others like them before, suggest that there is a fourth taste we are missing. This hypothetical particle may also well be an important component of dark matter. But this does not mean that a fourth type of elementary particle is the only explanation. The results of the experiment also raise the interesting possibility that our current theoretical framework describing neutrinos is defective. It would not be bad news at all. Science is an ongoing work in which the status quo is always accompanied by new, compelling evidence. In the process, the institution of science becomes stronger and more credible, as well as better equipped to answer increasingly complex questions about nature. The findings appeared in Physical Review Letters.