Latest news with #AstroparticleResearchwithCosmicsintheAbyss
Yahoo
3 days ago
- Science
- Yahoo
A Ghost Particle Flew Through Earth. It Might Have Come From Dark Matter.
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Here's what you'll learn when you read this story: In February of 2023, the Cubic Kilometer Neutrino Telescope (KM3NeT) detected a neutrino some 35 times higher in energy than any previous detection. A new study posits that this muon might be the result of a dark matter particle that decayed as it passed through the Earth, which would also explain why the IceCube Observatory in the South Pole hasn't detected any such particle. For now, the most likely explanation is that the particle is just a high-energy neutrino, but we're likely to learn more about these elusive particles when KM3NeT is fully online. In the middle of the night on February 13, 2023, the Astroparticle Research with Cosmics in the Abyss (ARCA) array—part of the larger Cubic Kilometer Neutrino Telescope (KM3NeT), located in the Mediterranean off the coast of Italy—detected a high-energy particle unlike any other. After crunching the numbers for two years, scientists earlier this year announced that this particle likely originated from a blazar, and was the highest-energy neutrino ever detected by a factor of 35. Even more impressive, the array documented this particle while it was only partially finished. However, there was one strange attribute of this neutrino event, which was dubbed KM3-230213A—the IceCube Neutrino Observatory in the South Pole has never recorded such an event, and did not detect this high-energy event, either. Now, a new study (posted to the preprint server arXiv) suggests that one way to resolve this conundrum is to consider if the ultra-energetic muon neutrino was actually produced by dark matter. 'It opens up a new way you can really test dark matter,' Bhupal Dev, lead author of the study from Washington University, said to New Scientist. 'We can convert these neutrino telescopes into dark matter detectors.' Because KM3-230213A traveled along a shallow path as it passed through out planet, it likely flew through more of the Earth's crust than it takes for neutrinos to reach IceCube—and that might be the key. The researchers tried to recreate a dark matter scenario that KM3NeT could detect, but IceCube could not. 'We propose a novel solution to this conundrum in terms of dark matter (DM) scattering in the Earth's crust,' the paper reads. 'We show that intermediate dark-sector particles that decay into muons are copiously produced when high-energy (∼100 PeV) DM propagates through a sufficient amount of Earth overburden.' So, the high-energy particle wasn't directly a dark matter particle, but rather a muon that decayed from dark matter likely fired from a blazar (a type of active galactic nucleus) right at Earth. As the paper notes, this is just one of many theories that have propagated since KM3NeT announced the discovery of the particle. These ideas suggest, according to the paper, that the particle could be 'decaying heavy DM, primordial black hole evaporation, Lorentz invariance violation, neutrino non-standard interactions.' The KM3NeT collaboration has detailed how the ARCA array—along with the Oscillation Research with Cosmics in the Abyss (ORCA) array—could provide indirect observations of dark matter similar to this event. However, other physicists speaking with New Scientist said that the most likely explanation (at least, as of right now) is that KM3-230213A is simply a high-energy neutrino, and not evidence of decaying dark matter. While hypotheses proliferate, scientists are still working with a sample size of one. But with K3MNeT finishing construction by the end of the decade, that likely won't be the case for long. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
19-02-2025
- Science
- Yahoo
A Detector at the Bottom of the Sea Found an Extraordinary Signal From the Unseen Universe
Neutrinos are arguably the most enigmatic particles in the universe, but scientists on Earth are getting better at detecting them. In February of 2023, the underwater Cubic Kilometer Neutrino Telescope (KM3NeT) detected a high-energy neutrino with 30 times more energy than any previously detected neutrino. Amazingly, KM3NeT detected this particle while under construction, using only 20 percent of its photodetectors. Neutrinos lie at the frontier of scientific unknowns about the universe. However, there's a problem—neutrinos also like to keep to themselves. They're the ultimate recluses of the particle physics world, but scientists have developed tools over decades to detect the reactions they can sometimes set off. One of those detectors is known as the Cubic Kilometer Neutrino Telescope (KM3NeT), which comprises two detector arrays anchored to the floor of the Mediterranean Sea. The Astroparticle Research with Cosmics in the Abyss (ARCA) array is located off the coast of Sicily, and in the middle of the night on February 13, 2023, the installation recorded an unusual signal—a high-energy muon streaking through the array in just a few microseconds. From the data, scientists determined that the muon contained 120 peta-electron volts (PeV) of energy, and further extrapolated that the instigating neutrino must have contained energies of 220 peta-electron volts—a level that's 30 times higher than any neutrino ever detected. The results of this astounding discovery were published in the journal Nature. 'Neutrinos are the closest thing to nothing that we can imagine,' Paschal Coyle, Centre national de la recherche scientifique (CNRS) researcher and KM3NeT spokesperson at the time of the detection, said during a press conference earlier this week, 'but they are key to fully understanding the workings of the universe.' Scientists don't directly detect neutrinos, but they can infer things about them by analyzing their interactions with the weak nuclear force (neutrinos also interact with gravity, but the effects are negligible). To give you a sense of how difficult it can be to detect a neutrino, scientists estimate that if 10 trillion neutrinos generated from the Sun pass through the Earth, only one will interact with a particle and produce a detectable reaction. Put another way, you could construct a lead wall five light years in width, and 50 percent of neutrinos could still pass through unscathed. So, not only did it come as a surprise when the ARCA array lit up in February of 2023, it was almost unbelievable that the experiment—which, at that time, had only deployed 10 percent of its photoreceptors—detected something as extraordinary as KM3-230213A (the name of the neutrino event). Two things make this particular muon (and, by extension, the neutrino that created it‚, particularly interesting. The first is its high energy level, which suggests a cosmic origin. The second is the angle of its trajectory. Because it was close to the horizon, it's likely that the neutrino collided with an atom in the deep sea surrounding the detector. 'Neutrinos are one of the most mysterious of elementary particles. They have no electric charge, almost no mass and interact only weakly with matter,' Rosa Coniglione from KM3NeT said in a press statement. 'They are special cosmic messengers, bringing us unique information on the mechanisms involved in the most energetic phenomena and allowing us to explore the farthest reaches of the universe.' Although the researchers can't be sure of the neutrino's origin, it's likely that the particle originated from a cataclysmic event like a gamma-ray burst, accreting supermassive black hole, or supernova explosion. It's also possible that energetic cosmic rays that ferried this neutrino to us interacted with protons found in the cosmic microwave background radiation, creating what's known as a 'cosmogenic neutrino.' KM3NeT is only at the beginning of its journey—this discovery popped up when the device was using only 21 of its planned 230 detection lines. And scientists are hopeful that this high-energy particle will be only the first of many similar discoveries. The project will also get a major assist in the exploration of neutrinos from the Deep Underground Neutrino Experiment, or DUNE, when it goes online in the coming years. Neutrinos may be the universe's most reclusive particles, but scientists are trying their best to bring some of their anti-social behaviors to light. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
