ALPHA Sharpens Antihydrogen Splitting Measurement 100-Fold With 25,000 Trapped Anti-Atoms
Updated
Updated · swansea.ac.uk · May 27
ALPHA Sharpens Antihydrogen Splitting Measurement 100-Fold With 25,000 Trapped Anti-Atoms
3 articles · Updated · swansea.ac.uk · May 27
More than 25,000 trapped antihydrogen atoms let the ALPHA collaboration measure the atom’s ground-state hyperfine splitting 100 times more accurately than before, marking its most precise probe yet of antihydrogen’s internal structure.
A new cooling method drove the gain: Swansea-led researchers used laser-cooled beryllium ions to sympathetically cool positrons, boosting the number of antihydrogen atoms produced and trapped for long-duration study at CERN.
The result, published in Nature, builds on a 4 ppm determination of the splitting and gives physicists a far sharper comparison point with ordinary hydrogen, the universe’s most abundant atom.
Researchers say combining this advance with ongoing 1S-2S spectroscopy could expose finer differences between hydrogen and antihydrogen, a clue to why the universe appears to contain so little antimatter.
With CPT symmetry holding firm, what is the next great mystery CERN’s Antimatter Factory will try to solve?
Could quantum gravity be the key to finally breaking the perfect symmetry between matter and antimatter?
If antimatter is a perfect mirror of matter, where did all the antimatter in our universe disappear to?
ALPHA Collaboration Achieves Record Precision in Antihydrogen Hyperfine Splitting, Tightening CPT Symmetry Constraints
Overview
In May 2026, the ALPHA Collaboration achieved a landmark by precisely measuring the ground-state hyperfine splitting of antihydrogen, a goal that has driven antimatter research since the 1990s and justified building the Antimatter Factory. This measurement, which mirrors the famous 21-cm line in hydrogen used by astronomers, now allows scientists to observe finer details in antihydrogen. By combining these results with advanced spectroscopy, researchers can compare matter and antimatter at an unprecedented level, deepening our understanding of the universe and testing fundamental physics principles that explain why matter dominates over antimatter.