Auburn researchers play role in antimatter breakthrough featured in journal Nature

RobicheauxA recent scientific breakthrough could lead to changes in the world of antimatter physics, according to Francis Robicheaux, an Auburn University physics professor and member of ALPHA, the international team of scientists conducting the antimatter research.

Last year the ALPHA (Anti-Hydrogen Laser Physics Apparatus) team was able to trap and hold the antimatter version of the hydrogen atom. They have now accomplished the goal they set at that time of being able to measure the fundamental properties of antihydrogen.

An article in this week’s edition of the journal Nature, titled “Resonant quantum transitions in trapped antihydrogen atoms,” describes the progress made in that research.The article reports that ALPHA has made yet another monumental step toward being able to make defendable and precise comparisons between atoms of matter and those of antimatter. Recently, Robicheaux and collaborators were able to measure the frequency needed to alter the magnetic properties of the antihydrogen atom by sending microwaves through the atom trap.

“This is the first baby step into doing great experiments with antihydrogen atoms,” Robicheaux said. “This is the first time any properties of antihydrogen have been measured with any type of precision.”

Patrick Donnan, sophomore in physics and music performance, helped Robicheaux with the calculations and is a co-author on the article.

“We performed computer simulations of how antihydrogen moves in the ALPHA trap and how the antiatoms respond to microwaves,” Donnan said. “Our simulations were used to optimize the parameters in the real experiment; since we're able to play with parameters very easily, we could run many scenarios to best determine what the experimentalists should do—optimizing the limited number of experiments able to be run.”

For years, the scientific world assumed that the properties of hydrogen and antihydrogen were exactly the same. However, without any way to explore the properties of antihydrogen, the theory could not be proved or disproved. This measurement is what Robicheaux hopes will change the world of antimatter physics, allowing research to advance on the antihydrogen properties.

“It’s very hard to improve experiments without a signal,” Robicheaux said, referring to the measurement as the signal. “Now, with this first signal, physicists can do improved experiments and start measuring new properties of the atom.”

When ALPHA’s earlier research initially made headlines, the team had captured 38 atoms of antihydrogen, storing each for a mere sixth of a second. They later made significant progress by trapping 309 antihydrogen atoms – some for as long as 15 minutes. As a result of the longer holding times Robicheaux and his collaborators set out to learn more about the properties of antihydrogen and work toward their ultimate goal of being able to perform different experiments on the atom – a goal now in reach for the ALPHA collaboration.

The research collaboration is headquartered at CERN, Europe's particle-physics lab near Geneva, Switzerland. ALPHA is mainly comprised of experimentalists who design, build and run the experiment, including scientists from Europe, Canada, the United States, Brazil, Israel and Japan. Robicheaux serves as a theorist to the team.

To read the article in Nature, go to http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10942.html.

To learn more about the ALPHA collaboration, go to http://alpha.web.cern.ch/alpha.

Last updated: 05/02/2013