--- title: "Physicists Say They’ve Found Evidence of Elusive Axion Particle" description: "An international team of physicists claim they may have found evidence for a new type of subatomic particle called the axion." date: "2020-06-17" modified: "2020-06-17" authors: - name: "Victor Tangermann" job_title: "Senior Editor" link: "https://futurism.com/authors/victor" url: "https://futurism.com/physicists-found-evidence-axion-particle" categories: - "Science & Energy" tags: - "axions" - "dark matter" - "neutrinos" - "tritium" --- # Physicists Say They’ve Found Evidence of Elusive Axion Particle ![]() *\Image: XENON Collaboration\* An international team of physicists claim they may have found evidence for a long-theorized type of subatomic particle called the axion. The axion was first suggested in the 1970s to explain discrepancies in particle physics. They have also become a popular way to explain the existence of dark matter, the nebulous stuff that makes up 85 percent of the mass of the universe. But scientists have never found direct evidence of them before — until, perhaps, now. As part of the XENON1T Dark Matter Experiment, detailed in a [lengthy *New York Times* story]() about the discovery, researchers set up two tons of ultra-pure liquefied xenon in a vat under an Italian mountain. Xenon is a noble gas that is extremely stable, an inertness that makes it a perfect candidate to detect the presence of any particles that pass through it. ![]() The team [announced]() that they found a "surprising excess of events" of particles interacting with the xenon particles — events that the scientists couldn't account for using the standard model of physics. The scientists suggest there are three explanations for this excess. One is contamination in the tank. It could also be caused by neutrinos, a well-established particle. The third explanation is far more bold, and could have sweeping implications in the world of physics. The interactions could be as a result of axions — potentially the first observation of the elusive particle. While axions are not currently a proposed direct explanation for dark matter, they could've set the stage for the creation of dark matter in the early stages of our universe. Scientists are undeniably excited by this third possibility, though they're also urging restraint due to the other potential explanations. "I’m trying to be calm here, but it’s hard not to be hyperbolic,” Neal Weiner, a particle theorist at New York University, who was not involved in the research, told *The New York Times*. "If this is real, calling it a game changer would be an understatement." "If this bears out, and *if* is a big question, this is the biggest game changer in my corner of physics since the discovery of cosmic acceleration," Chanda Prescod-Weinstein, a physicist at the University of New Hampshire who also wasn't involved, [told *Live Science*]() in an email. Others are calling for more time before popping the champagne corks. "Despite being excited about this excess, we should be very patient," Luca Grandi, a physicist at the University of Chicago and co-author of the yet-to-be-peer-reviewed [paper](), [told *Quanta Magazine*](). A much larger experiment, with sensitivity levels dialed up, had to be delayed by the coronavirus lockdown in Italy. It may still take place later this year, according to the *Times*. To put the statistics in perspective, Kai Martens, a physicist at the University of Tokyo who worked on the experiment, told *Live Science* that there's about a 2 in 10,000 chance that random background radiation was behind the excess events rather than axions themselves. That kind of probability falls well short of the threshold physicists typically try to achieve before considering a discovery to be well-established. So far, the dominant explanation for the existence of dark matter has been the existence of so called "weakly interacting massive particles," which have the amusing acronym "WIMPs." WIMPs are hypothetical particles that are extremely high in mass and could account for most if not all of dark matter. But over time, physicists have become increasingly interested in exploring the possibility of axions as well. **READ MORE:** [Seeking Dark Matter, They Detected Another Mystery]() \[*The New York Times*\] **More on axions:** *[Scientists May Have Identified the Particles That Make Up Dark Matter]()* ## Author I've been at Futurism since 2017, where my role has evolved to encompass design, writing, and increasingly editing. I've always been fascinated by space exploration and advanced transportation, which I've leaned into by interviewing luminaries in those fields while closely following the dimensions of policy and regulation that allow next-generation projects to succeed -- or, sometimes, to fail. I'm also keenly interested in the effects of generative AI on society, policies, and democratic institutions, as well as clean energy, physics and biology, and the vagaries of tech leadership. My work for Futurism has been cited by publications including Ars Technica, Gizmodo, PC Magazine, Jalopnik, Fox News, and the New York Post. I spent my childhood living in locations including Manila, the Philippines, and Geneva, Switzerland, attended McGill University, and now live in Toronto, Canada. Before Futurism I worked at AskMen and a small photography studio. In my free time, I'm an avid gardener, foodie, and craft beer lover, as well as a maker of artisanal hot pepper sauces. I have a magnificent dog named Freida. ### Author social links [Bluesky]()