Although the above description may sound like it just came out of a scene from The X Files, what it actually describes is the setting for a recent experiment aimed at confirming the possible existence of a new elementary particle: the sterile neutrino. The Baksan Neutron Observatory is without a doubt one of the most unusual laboratories anywhere in the world. Located beneath the Baksan River Gorge in the Russian Caucasus, construction began in 1977 and today houses an extensive network of underground facilities hosting an arsenal of technological marvels, including the Baksan Underground Spark Telescope (BUST). From 2019, the site also hosts the Baksan Experiment for Sterile Transitions (BEST), a study conducted in a 4,000-meter horizontal tunnel that extends down the slopes of Mount Andyrchi. An extension of experiments that began in the 1980s as a joint research effort between the Soviets and the United States to measure solar neutrino flux, BEST researchers have spent several years on new knowledge of physics that can even help throw light in the dark matter. of the greatest mysteries of the universe. Now, according to a new scientific paper describing the results of an ongoing experiment, confirming an anomaly that has long confused physicists could mean that science is close to confirming the existence of sterile neutrinos. This, or may suggest the possibility that something might be wrong with our current understanding of the typical model of physics. “The results are very exciting,” said Steve Elliott, chief analyst at the Department of Physics at the Los Alamos National Laboratory, which is working on the BEST experiment. “This certainly confirms the anomaly we have seen in previous experiments,” Eliot said in a statement released by the Los Alamos National Laboratory. “But what that means is not obvious.” At the heart of the mystery is the sterile neutrino, another hypothetical particle that physicists identify as unique – if any – because of the way in which their interactions relate only to gravity, in contrast to other types of interactions identified in the model. Neutrinos are currently known to exist in three types: electron, muon and tau. Previous experiments in 2007 at the Fermi National Accelerator Laboratory in Batavia, Illinois, failed to detect data for a fourth neutron variety. However, the results of the new BEST study may have once again shaken the foundations of the established model, thus revitalizing questions that remain about our understanding of physics. “There are now conflicting results about sterile neutrinos,” says Eliot. “If the results indicate that fundamental nuclear or atomic physics has been misunderstood, that would also be very interesting.” In a recent study, BEST researchers found that the production rates of a particular isotope, germanium 71, were found to be almost up to 25% lower than predicted in the standard model. Germanium 71 was produced using a set of 26 disks made from another isotope – chromium 51 – which served as the reaction point between neutron electrons and gallium. The two-band gallium target used in the recent experiment, which is irradiated by a neutrino electron source (Credit: AA Shikhin). This is important because it aligns with earlier observations of the anomaly first detected by researchers in previous experiments beginning in the 1980s. The Soviet-American Experiment of Gallium, or SAGE, known to be high intensity. The SAGE experiments were the first to notice the so-called “gallium abnormality” that was re-identified during the recent BEST experiments.
Although there is more than one possible explanation for the anomaly, the oscillation of electron neutrino particles in their hypothetical sterile neutrino states is among the interpretations examined by the researchers. If this were to be the cause of the gallium deficiency in both experiments, it would be significant because sterile neutrinos may be a component of the mysterious dark matter believed to exist throughout the universe, parts of which may be composed of weakly interacting particles. . However, there may be other interpretations that could better explain the anomaly. Researchers at Elliot and Los Alamos reviewing the BEST results found that some of the information currently missing from the researchers included measurements of the neutrino electron cross section at actions comparable to those in the BEST and SAGE experiments. One possible way to achieve such measurements could involve revealing another conundrum in physics: the idiosyncratic density of electrons within the atomic nucleus, which has been proposed as a possible input for measuring neutron cross-section. To reduce the possibility of error, special attention was paid to the use of measurement systems, as well as to the sources of radiation, their placement and other elements in the experiment. However, given the possibility that some theoretical inputs may remain in question, it may turn out that there are aspects of physics that work in experiments that will require re-examination. Looking to the future, BEST may attempt to repeat the experiment with small changes involving a different radiation source, capable of producing shorter oscillation wavelengths based on its half-life breakdown rate. If the same observations of “lost” neutron electrons occur in future experiments, contrary to the predicted results according to the standard model of physics, it may indeed indicate the reality of the sterile neutrino they have been looking for for a long time, and therefore a deeper understanding of the fine mechanics of our universe.
