Latest news with #NationalInstituteforNuclearPhysics
NBC News
5 days ago
- General
- NBC News
A long-running experiment finds a tiny particle is still acting weird
NEW YORK — Final results from a long-running U.S.-based experiment announced Tuesday show a tiny particle continues to act strangely — but that's still good news for the laws of physics as we know them. 'This experiment is a huge feat in precision,' said Tova Holmes, an experimental physicist at the University of Tennessee, Knoxville who is not part of the collaboration. The mysterious particles called muons are considered heavier cousins to electrons. They wobble like a top when inside a magnetic field, and scientists are studying that motion to see if it lines up with the foundational rulebook of physics called the Standard Model. Experiments in the 1960s and 1970s seemed to indicate all was well. But tests at Brookhaven National Laboratory in the late 1990s and early 2000s produced something unexpected: the muons weren't behaving like they should. Decades later, an international collaboration of scientists decided to rerun the experiments with an even higher degree of precision. The team raced muons around a magnetic, ring-shaped track — the same one used in Brookhaven's experiment — and studied their signature wiggle at the Fermi National Accelerator Laboratory near Chicago. The first two sets of results — unveiled in 2021 and 2023 — seemed to confirm the muons' weird behavior, prompting theoretical physicists to try to reconcile the new measurements with the Standard Model. Now, the group has completed the experiment and released a measurement of the muon's wobble that agrees with what they found before, using more than double the amount of data compared to 2023. They submitted their results to the journal Physical Review Letters. That said, it's not yet closing time for our most basic understanding of what's holding the universe together. While the muons raced around their track, other scientists found a way to more closely reconcile their behavior with the Standard Model with the help of supercomputers. There's still more work to be done as researchers continue to put their heads together and future experiments take a stab at measuring the muon wobble — including one at the Japan Proton Accelerator Research Complex that's expected to start near the end of the decade. Scientists also are still analyzing the final muon data to see if they can glean information about other mysterious entities like dark matter. 'This measurement will remain a benchmark ... for many years to come,' said Marco Incagli with the National Institute for Nuclear Physics in Italy. By wrangling muons, scientists are striving to answer fundamental questions that have long puzzled humanity, said Peter Winter with Argonne National Laboratory.
USA Today
12-02-2025
- Science
- USA Today
Discovery: Powerful 'ghost particle' with clues about the universe
Discovery: Powerful 'ghost particle' with clues about the universe They're tiny, invisible, and travel across the universe. And trillions of them just flew through your body. What are they? Neutrinos ‒ and scientists Wednesday announced the discovery of the most powerful one ever seen. Neutrinos are ghostly subatomic particles that can travel in a straight line for billions of light-years, passing unhindered through galaxies, stars and anything else in their path. Because they rarely interact with matter and have almost no mass they are often referred to as "ghost particles." The newly discovered neutrino's energy is estimated to be around 30 times higher than any neutrino previously detected. The result suggests that the particle came from beyond our Milky Way, although its precise origin remains to be determined. The new research was published Wednesday in the peer-reviewed British journal Nature. What are neutrinos? Difficult to detect, neutrinos are extremely tiny particles and are among the most abundant in the universe. They don't interact much with anything and travel close to the speed of light. 'Neutrinos are one of the most mysterious of elementary particles," explained Rosa Coniglione, researcher at the National Institute for Nuclear Physics in Italy, one of the scientists who made the discovery. "They have no electric charge, almost no mass and interact only weakly with matter. 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 neutrinos are the second most abundant particle in the universe after photons, their weak interaction with matter makes them very hard to detect and requires enormous detectors, such as the one that made this discovery. This particle was spotted by the Cubic Kilometer Neutrino Telescope (KM3NeT), a collection of light-detecting glass spheres on the floor of the Mediterranean Sea, on February 13, 2023, according to Nature. How energetic was the neutrino? The neutrino in question was 30 times more energetic than any other neutrino detected to date, a quadrillion times more energetic than particles of light called photons and 10,000 times more energetic than particles made by the world's largest and most powerful particle accelerator, the Large Hadron Collider near Geneva. "The energy of this neutrino is exceptional," added physicist Aart Heijboer of the Nikhef National Institute for Subatomic Physics in the Netherlands, another of the researchers. Where do neutrinos come from? High-energy neutrinos arise from particle collisions occurring in violent events such as a black hole eating matter or bursts of gamma rays during the explosive deaths of stars. They also can be produced by interactions between high-energy cosmic rays and the universe's background radiation. Scientists say the study of neutrinos is still in its formative stages. "It's basically just trying to understand what is going on in the cosmos," Heijboer said. Contributing: Jessica Bies, The News Journal; Reuters
