March 5, 2020
草莓污视频导航 researchers help international team with first-ever measurement of small quantum effect in antimatter
New research on is moving science closer to potentially solving one of the Universe鈥檚 greatest mysteries. In a new experiment, ALPHA has reported the first measurement of small quantum effects in antihydrogen 鈥 hydrogen鈥檚 antimatter counterpart 鈥 and their findings show that, at least in this instance, the atoms show similarities.
The collaboration is a world-leading international collaboration operating at the laboratory near Geneva, Switzerland, and includes researchers from the in the .
ALPHA鈥檚 most recent experiment on antimatter sought to determine if any differences existed between the properties of hydrogen and antihydrogen.
- Photo above: 草莓污视频导航's Robert Thompson with PhD student, Andrew Evans. Photo by Riley Brandt, 草莓污视频导航
The results, described in a paper recently published in the journal Nature, show that these first measurements are consistent with theoretical predictions of the effects in normal hydrogen. Essentially, antimatter hydrogen has the same 鈥渜uantum quirk鈥 as normal hydrogen. Studying these small effects could reveal differences between the behaviour of matter and antimatter.
鈥淭his work is the first experimental measurement of the Lamb shift in antihydrogen and finds that, within the precision of our experiment, this shift is identical to that of regular hydrogen. This work confirms that this key element of quantum electrodynamics also holds in antimatter and represents an important step in our understanding of antimatter,鈥 says , PhD, assistant professor in the Department of Physics and Astronomy.
草莓污视频导航 made essential contributions to discovery
, PhD, 草莓污视频导航鈥檚 Associate Vice-President (Research) and Director of Research Services, is a longtime ALPHA team member and researcher who is leading the coordination of the 草莓污视频导航鈥檚 contribution to ALPHA鈥檚 antimatter experiments.
鈥淲hen ALPHA started, we were often viewed as a little different, thinking we could store antihydrogen. Then we did it. After that, people were skeptical that we could detect a spectroscopic signal 鈥 we proved we were able to do that, too. Now, work like this shows that we are pushing precision spectroscopy of antihydrogen to levels that will test the foundations of subatomic physics,鈥 he says.
The fabricated major portions of the cryostat, a liquid helium cooled ultra-high vacuum chamber used to cool the antihydrogen trap to four degrees above absolute zero Kelvin.
Thompson鈥檚 PhD student, , was instrumental in the success of this experiment from start to finish. He was part of the small team that developed and operated the laser system and its complex interface with the ALPHA antihydrogen trap. Andrew also wrote the software to compile and analyse the data.
鈥淭he main challenges were keeping the laser running, testing and troubleshooting the experimental equipment, and writing software used in compilation of the datasets,鈥 Evans explains. 鈥淪o many different parts needed to be working perfectly, and all at the same time, in order for this set of data to be taken. It took a lot of paranoia and last-minute panics to get everything just right.鈥
Friesen built the trap that was used to combine the positrons and antiprotons to form antihydrogen atoms. During these measurements, Friesen was also the Technical Coordinator for the ALPHA experiment, and was responsible for overseeing upgrades, modifications, and operations of the experimental equipment.
Contributed
Measurement important step in advancing understanding of antimatter
Physics dictates that for every particle of matter there is an oppositely charged antiparticle with an equal mass. An antihydrogen atom should have the exact same charge as hydrogen (zero). That鈥檚 because the antiproton and antielectron (positron), which make up antihydrogen, have the exact opposite charge of the proton and electron that make up hydrogen.
Historically, antimatter particles have been difficult to study, as they can only be made travelling close to the speed of light. When antimatter and matter particles come into contact with each other, they annihilate in a flash of energy.
The ALPHA team creates antihydrogen atoms by binding antiprotons delivered by with positrons, which are then confined in a magnetic trap in an ultra-high vacuum, preventing them from coming into contact with matter and destructing. 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.
鈥淭he observation of the Lamb shift in hydrogen in 1947 was a pivotal measurement in modern physics,鈥 Friesen explains. 鈥淚t showed that there was a small unexpected energy difference between two electron orbitals. This inspired the development of quantum electrodynamics, the theory that describes how light and matter interact.鈥
ALPHA is now constructing a new vertical antihydrogen apparatus, known as ALPHA-g, to measure whether antimatter will fall exactly like matter in Earth鈥檚 gravity.
The laser system used in this work can also be applied to laser cool large samples of antihydrogen, which will allow ALPHA to study antihydrogen at much higher levels of precision.
ALPHA-g is a project led by the 草莓污视频导航, with funding provided by Canada, including contributions from Alberta, British Columbia, and Ontario.
Modern physics states that the universe is made up of equal amounts of matter and antimatter. Researcher Dr. Rob Thompson, PhD, 草莓污视频导航鈥檚 Associate Vice-President (Research) and Director of Research Services, explains his quest to learn about the universe's most elusive particles.
Explore 草莓污视频导航 (explore.ucalgary.ca)