This is an animation of the ALPHA apparatus used by CERN researchers to manipulate antihydrogen atoms using microwaves, providing the first glimpse of an “anti-atomic fingerprint.” Credit: ALPHA collaboration (CERN)
The properties of antimatter atoms have been measured as part of the Antihydrogen Laser Physics Apparatus (ALPHA) experiment at the European Organization for Nuclear Research (CERN).
Antimatter is made up of particles like ordinary matter, but with opposite charges and magnetic properties, for example antihydrogen atoms are the opposite to hydrogen atoms.
Based on the idea that the universe was created during the big bang 13.6 billion years ago, there should be equal amounts of matter and antimatter present. However, antimatter is rare and has only been detected briefly, for example, in cosmic rays and some radioactive materials.
An international team of scientists captured antihydrogen atoms using magnets, and then bombarded them with microwaves, causing them to vibrate. When the antimatter reached a particular frequency of vibration—its internal resonance—it jumped out of the magnetic trap. The precise magnetic field and radiation frequency required to do this showed the researchers hydrogen’s “anti-atomic fingerprint,” giving them an insight into the structure of these mysterious particles.
“For decades, scientists have wanted to study the intrinsic properties of antimatter atoms in the hope of finding clues that might help answer fundamental questions about our universe,” said study lead author Mike Hayden at Canada’s Simon Fraser University (SFU) in a press release.
“In the middle of the last century, physicists were developing and using microwave techniques to study ordinary atoms like hydrogen,” he added. “Now, 60 or 70 years down the road, we have just witnessed the first-ever microwave interactions with an anti-atom.”
With this highly sensitive technique, the researchers can begin to better understand antimatter’s inner structure.
“This study demonstrates the feasibility of applying microwave spectroscopy to fiendishly difficult-to-handle anti-atoms,” said study co-author Walter Hardy at Canada’s University of British Columbia (UBC) in the release.
ALPHA will shortly be upgraded in its ability to produce more details of antimatter’s nature.
“Hydrogen is the most abundant element in the universe, and we understand its structure extremely well,” said ALPHA collaboration spokesperson Jeffrey Hangst at Denmark’s Aarhus University in the release. “Now we can finally begin to coax the truth out of antihydrogen.”
“Are they different?” he asked. “Today, we can confidently say ‘time will tell.'”
The findings will be published in Nature on March 8.