University of Calgary researchers are a part of a group who just got one step closer to solving a mystery of the universe. Dr. Timothy Friesen, Ph.D., an associate professor of Physics and Astronomy in the Faculty of Science, and his team led a new measurement comparing the spectrum of hydrogen to its antimatter counterpart—antihydrogen.
The results of this new measurement are published in the journal Nature.
“Fairly core in our theoretical models is the symmetry between matter and antimatter, and if that symmetry is broken there would be a huge impact on how we construct those theories and how we think about our absolute laws in physics,” says Friesen.
The measurements were performed by ALPHA, an international collaboration of approximately 60 scientists operating at the CERN laboratory near Geneva, Switzerland.
At the precision achieved in this measurement, Friesen and the group found that the symmetry between hydrogen and antihydrogen predicted by current theory holds.
According to the laws of physics, matter and antimatter should mirror each other, the only difference being their charge. However, when matter and antimatter meet, they destroy each other.
This leads to one of the great mysteries of the universe, because after the Big Bang everything would have been annihilated if there were equal amounts of matter and antimatter. Since the universe is made almost entirely of matter, there must be a tiny hidden difference between the two.
In this measurement, the scientists were looking at a property called the hyperfine splitting, a small energy difference that arises because the antiproton and antielectron (positron) behave like tiny interacting magnets. In matter hydrogen, the size of the splitting is known extremely well and so measuring it in antihydrogen is an attractive way to search for any potential difference between matter and antimatter.
“If we found even a miniscule difference it would break our current understanding of physics and it’s something we need to investigate,” explains Friesen.
This is the second time researchers have measured this property of antihydrogen. The first time was in 2017, and this time the testing was 100 times better.
It marks a step towards being able to test antihydrogen to the same level of precision that hydrogen is currently evaluated at.
Antihydrogen is very difficult to produce and contain, so the researchers had to build a containment system that created a vacuum similar to outer space and uses strong superconducting magnets to ensure the antimatter atoms do not contact the walls of the container.
The next steps will be to continue refining the precision of the testing. Friesen says the next major milestone will be measuring the properties of antihydrogen at the same level of precision as hydrogen. After that, scientists will have to start improving the measurements of both hydrogen and antihydrogen.
Friesen says the smallest difference would question the current understanding at a fundamental level.
Publication details
R. Akbari et al, Four ppm measurement of the antihydrogen ground-state hyperfine splitting, Nature (2026). DOI: 10.1038/s41586-026-10556-x
Provided by
University of Calgary
Citation:
Antihydrogen mirrors hydrogen in upgraded spectrum test, narrowing cosmic mystery (2026, May 29)
retrieved 29 May 2026
from https://phys.org/news/2026-05-antihydrogen-mirrors-hydrogen-spectrum-narrowing.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.