The ALPHA collaboration at CERN has reported the first measurements of certain quantum effects in the energy structure of antihydrogen, the antimatter counterpart of hydrogen.
These quantum effects are known to exist in matter, and studying them could reveal as yet unobserved differences between the behavior of matter and antimatter. The results show that these first measurements are consistent with theoretical predictions of the effects in “normal” hydrogen, and pave the way for more precise measurements of these and other fundamental quantities.
The ALPHA team creates antihydrogen atoms by binding antiprotons delivered by CERN’s Antiproton Decelerator with antielectrons, more commonly called positrons. It then confines them in a magnetic trap in an ultra-high vacuum, which prevents them from coming into contact with matter and annihilating. Laser light is then shone onto the trapped atoms to measure their spectral response. This technique helps measure known quantum effects like the so-called fine structure and the Lamb shift, which correspond to tiny splittings in certain energy levels of the atom, and were measured in this study in the antihydrogen atom for the first time.
The paper has been published in the journal Nature. (CERN)