CERN physicists have noticed a benchmark transition of atomic energy in antihydrogen for the first time, which represents a key step toward cooling and exploiting the fundamental form of antimatter.
“The Lyman-alpha transition is the most basic, important transition in regular hydrogen atoms, and to capture the same phenomenon in antihydrogen opens up a new era in antimatter science,” stated Takamasa Momose, the University of British Columbia chemist and physicist who headed the fabrication of the laser system used for exploiting the antihydrogen.
“This approach is a gateway to cooling down antihydrogen, which will greatly improve the precision of our measurements and allow us test how antimatter and gravity interact, which is still a mystery.”
The results of the study have been reported in Nature.
It is very difficult to capture and work with antimatter, which is annihilated on impact with matter. However, the study of antimatter is important for solving one of the universe’s greatest mysteries - why anti-matter that should have existed in equivalent amounts to matter during the time of the Big Bang has completely disappeared?
“This gets us just a bit closer to answering some of these big questions in physics,” stated Makoto Fujiwara, Canada’s spokesperson for CERN’s ALPHA antihydrogen research collaboration, and also a physicist with TRIUMF, Canada's particle accelerator centre. “Over the past decades, scientists have been able to revolutionize atomic physics using optical manipulation and laser cooling, and with this result we can begin applying the same tools to probing the mysteries of antimatter.”
Containing a positron and antiproton, the antihydrogen atom is the antimatter counterpart of a hydrogen atom, made of one proton with an orbiting electron.
The supposed Lyman-alpha transition, initially observed in hydrogen over a century ago, is quantified as a series of ultraviolet emissions when the electron of a hydrogen atom is made to shift to a high orbital from a low orbital. With the help of laser pulses that last nano seconds, Fujiwara, Momose, Canadian colleagues, as well as the international ALPHA collaboration at CERN, successfully accomplished the same energy transition in many antihydrogen atoms that were magnetically trapped in a vacuum.
In addition to the extreme challenge of capturing several hundred antihydrogen atoms sufficiently long to work with them, adjusting the components of the laser system took years.
You can’t actually see the laser pulses you’re using to excite the antihydrogen and shift the orbitals. So, our team was essentially working and trouble-shooting the laser system in the blind!
The next step of the team is to utilize the laser innovation to help create cold and thick sample of anti-atoms for gravity measurements and precision spectroscopy.