New research published today by researchers from CERN has brought us a step closer to understanding where all the antimatter has gone. This matter-antimatter asymmetry is one of the greatest challenges in physics and at this moment in time the universe seems to be composed entirely of matter – the only antimatter around is created by us at places like CERN. Yet our theories predict that exactly equal amounts of matter and antimatter would have been created in the Big Bang. So where did all the antimatter go?
This new research, undertaken by the ALPHA experiment at CERN's Antiproton Decelerator (AD) in Geneva, is the first time that the electric charge of an anti-atom has been measured to high precision. Measuring the electric charge of antihydrogen atoms is a way to study any subtle differences between matter and antimatter which could account for the lack of antimatter in the universe.
In a paper published in the journal Nature Communications today, the ALPHA experiment reports a measurement of the electric charge of antihydrogen atoms, finding it to be compatible with zero to eight decimal places. This is the first time that the charge of an anti-atom has been measured to high precision and confirms our expectation that the charges of its constituents, the positron and antiproton, are equal and opposite.