by Register for CNNS Wonder Theory Science Newsletter. Explore the universe with news about fascinating discoveries, scientific progress and more.
Scientists try to solve a secret of decades by determining the identity of anomal signals that have been detected in the Antarctic from below ice.
The strange radio waves appeared during a search for another unusual phenomenon: energy -rich cosmic particles that are known as neutrinos. The neutrinos are often referred to as “ghostly” because they are extremely fleeting or steamed and can go through any kind of matter without changing, often as “ghostly”.
In the past ten years, researchers have carried out several experiments with huge water and ice surfaces that are supposed to search for neutrinos, which could shed light on mysterious cosmic rays that could illuminate the highest energetic particles in the universe. One of these projects was the Antarctic impulsive transient antenna or Anita experiment by NASA, which exceeded balloons over the Antarctic between 2006 and 2016.
During this hunting, Anita recorded anomal radio waves that didn’t seem to be neutrinos.
The signals came from the horizon, which indicates that they had driven thousands of kilometers of rock before reaching the detector. But the radio waves should have been absorbed by the rock. The Anita team believed that these anomal signals could not be explained by the current understanding of particle physics.
Follow-up observations and analyzes with other instruments, including a recently carried out Observatory in Argentina, could not find the same signals. The results of the Pierre Auger Collaboration were published in the magazine Physical Review Letters in March.
The origin of the anomal signals remains unclear, said the study, the co -author Stephanie Wissel, Associate Professor of Physics, Astronomy and Astrophysics at Pennsylvania State University.
“Our new study shows that such (signals) were not seen by an experiment like the Pierre Auger Observatory,” said Wissel. “So it does not show that there is new physics, but more information that can be added to the story.”
Larger, more sensitive detectors may be able to solve the secret or ultimately prove whether the anomal signals were a coincidence, while the search for puzzling neutrinos and their sources continues, scientists say.
The search for neutrinos
By recognizing neutrinos on earth, researchers can trace them back on their sources, of which scientists are mainly cosmic rays that affect the atmosphere of our planet.
Cosmic rays, the most highly energetic particles in the universe, mainly consist of protons or nuclear cores, and they are unleashed over the universe, since everything that produces it is such a strong particle accelerator that it puts the skills of the large Hadron collider in the shade. Neutrinos could help astronomers better understand cosmic rays and what starts them through the cosmos.
But neutrinos are difficult to find because they have almost no mass and the most extreme environments, such as stars and entire galaxies, can go through unchanged. However, they interact with water and ice.
Anita was developed to search for the highest energy neutrinos in the universe with higher energies than before, said Justin Vandenbroucke, Associate Professor of Physics at the University of Wisconsin, Madison. The radio antennas of the experiment are looking for a short pulse of radio waves that are generated when a neutrino collides with an atom in an antarctic ice, which leads to a shower of particles with lower energy.
During his flights, Anita found energy -rich wells of particles from the ice, a species on the head cosmic rays. The detector is also sensitive to ultra -hole cosmic rays that rain on earth and create a radio burst that acts like a flashlight of radio waves.
When Anita observes a cosmic beam, the flashlight beam is really a process of radio waves that can be mapped like a wave for a billion seconds to show how it is reflected by the ice.
An anomaly in the data
Twice in her data from Anita flights, the original team of the experiment discovered signals, which stood by models through the ice in a much sharper angle than ever before, which makes it impossible to pursue the signals on their original sources.
“The radio waves that we discovered almost a decade ago were in really steep angles like 30 degrees below the surface of the ice cream,” said Wissel.
Neutrinos can travel through a lot of matter, but not all the way through the earth, said Vandenbroucke.
“It is expected to arrive slightly below the horizon where there is not much soil that you can absorb,” he wrote in an e -mail. “The anomal events of Anita are fascinating because they seem to come from far below the horizon, so that the neutrinos would have to travel through a large part of the earth. This is not possible according to the standard model of particle physics.”
Anita’s instruments were developed to recognize radio waves from cosmic rays that joined the atmosphere. – Stephanie Wissel/Penn State
The cooperation between Pierre Auger, which includes hundreds of scientists around the world, analyzed data more than a decade to try to understand the anomal signals found by Anita.
The team also used his observatory to try to find the same signals. The AUGER -OBSCONTATION is a hybrid detector that uses two methods to find and examine cosmic rays. One method is based on the search for energy -minded particles when they interact with water in tanks on the earth’s surface, and the other pursues potential interactions with ultraviolet light in the atmosphere of our planet.
“The AUGER Observatory uses a completely different technology to observe cosmic rays of cosmic rays, whereby the secondary glow of invited particles is used, while crossing the atmosphere to determine the direction of the cosmic beam that initiated it,” said Peter Gorham, Professor of Physics at the University of Hawaii in Mānoa. “By using computer simulations of what such a particle shower would look like if it had behaved like the anomal events of Anita, you can generate a kind of template for similar events and then search for your data to see if something like this appears.”
Gorham, who was not involved in the new research, designed the Anita experiment and carried out other research to understand more about the anomal signals.
While the AuGer Observatory was designed so that particle showers were produced down in the atmosphere by cosmic ultra-hole-andtered cosmic rays, the team has redesigned their data analysis to look for upward air showering, said Vandenbrouck. Vandenbroucke did not work on the new study, but he checked it before publication.
“Auger has an enormous collective area for events that are greater than Anita,” he said. “If the Anomal Anita events are created by particles that drive through the earth and then produced to upward schools, the augers should have discovered many of them, and it didn’t.”
A separate follow-up study using the IceCube experiment, in which sensors are deeply embedded in the antarctic ice, also searched for anomal signals.
“Since Icecube is very sensitive, we would have discovered it if the anomal events of anomal anita events were,” wrote Vandenbroucke, who acted as a Colead Icecube Neutrino sources between 2019 and 2022.
“It is an interesting problem because we still have no explanation for what these anomalies are, but we know that they most likely do not represent Neutrinos,” said Wissel.
Strangely enough, a different kind of neutrino, which is referred to as Tau -Neutrino, is a hypothesis that some scientists have highlighted as the cause of the anomal signals.
Tau -Neutrinos can regenerate. If you fall for high energies, you produce another Tau -Neutrino and a particle called Tau Lepton – similar to an electron, but much more difficult.
However, what makes the Tau -Neutrino scenario very unlikely is the steepness of the angle connected to the signal, said Wissel.
“They expect all of these dew neutrinos to be very, very close to the horizon, like perhaps one to five degrees below the horizon,” said Wissel. “These are 30 degrees below the horizon. There is simply too much material. They would really lose a lot of energy and not be demonstrable.”
The future of recognition
Ultimately, Gorham and the other scientists have no idea what the origin of the Anomal Anita events is. So far, no interpretations correspond to the signals, which repeatedly withdraw scientists to try to solve the secret. However, the answer can be in sight.
Wissel also works on a new detector, the payload for ultra -hohe energy observations or Pueo, which will fly over the Antarctic for a month from December. Pueo, larger and ten times more sensitive than Anita, could reveal more information about what the anomal signals discovered by Anita, said Wissel.
The Anita experiment flew four times between 2006 and 2016. – Stephanie Wissel/Penn State
“At the moment it is one of these long -term secrets,” said Wissel. “I am excited to see that we have a better sensitivity when flying from Pueo. In principle, we should be able to better understand these anomalies, which makes a great contribution to understanding our backgrounds and ultimately records neutrinos in the future.”
Gorham said that Pueo, an acronym that refers to the Hawaiian owl, should have sensitivity to record many anomal signals and to help scientists to find an answer.
“Sometimes you just have to return to the drawing board and really find out what these things are,” said Wissel. “The most likely scenario is that it is a secular physics that can be explained, but we knock on all doors to find out what they are.”
More CNN messages and newsletter create an account at CNN.com
