CERN scientists trace the structure of 'home-made' anti-matter

Findings could help astronomers map the universe

Scientists have traced the structure of antihydrogen, the antimatter counterpart of hydrogen, for the first time by using a spectroscopic technique - a development that could help transform astrophysics.

The scientists claim that their findings could make it easier for astronomers to explore the expanding universe and determine why it actually contains planets.

The researchers, based at the European Organisation for Nuclear Research (CERN), have spent the past few months exploring antihydrogen, the mirror particle of hydrogen.

Nine months ago, CERN scientists achieved a ground-breaking discovery when they were able to measure the spectrum of light that comes from the particle.

However, more recently, they have been working with a Canadian research team under Alpha Collaboration, a group of physicists from about 11 universities who work together to try to trap neutral antimatter. Together, they have have managed to crack open antihydrogen's structure.

Just like hydrogen, it sports spectral lines - and both varieties happen to be identical. In the past, scientists believed that hydrogen and antihydrogen would lack any similarities.

For decades, astronomers have attempted to explore the nature of matter in the universe and, in particular, to work out the composition of the matter that makes up the universe.

There are, broadly speaking, two kinds of matter, but the universe only appears to be made of one of them. This has puzzled scientists, although the 'standard model' of physics claims that particles have a twin variant.

Through the Collaboration, scientists have been trying to find differences in these two matters. To do this, they used the CERN' Antiproton Decelerator, which was able to process 90,000 antiprotons.

Next, the scientists paired antiprotons with positrons to create antihydrogen. In total, they created 1.6 million positrons and 25,000 antihydrogen atoms.

Justin Munich, one of the researchers on the project, explained that her team had to keep these particles apart in order to generate a successful outcome.

"We can't just put our anti-atoms into an ordinary container. They have to be trapped or held inside a special magnetic bottle," she said.

Overall, the team trapped and detected 194 atoms, demonstrating how complex it can be to study simple forms of antimatter. But the researchers were still able to explore antihydrogen.

They found that when antihydrogen is exposed to electromagnetic radiation, it absorbs the impact and sends out a wave of light to fight back.

"Spectral lines are like fingerprints. Every element has its own unique pattern," added co-researcher Michael Hayden, from Simon Fraser University

Jeffrey Hangst, spokesperson for Alpha, added: "Spectroscopy is a very important tool in all areas of physics. We are now entering a new era as we extend spectroscopy to antimatter.

"With our unique techniques, we are now able to observe the detailed structure of antimatter atoms in hours rather than weeks, something we could not even imagine a few years ago."