Nav: Home

First observation of the hyperfine splitting in antihydrogen

August 03, 2017

Swansea University scientists working at CERN have again made a landmark finding, taking them one step closer to answering the question of why matter exists and illuminating the mysteries of the Big Bang and the birth of the Universe.

In their paper published in Nature the physicists from the University's College of Science, working with an international collaborative team at CERN, describe the first observation of spectral line shapes in antihydrogen, the antimatter equivalent of hydrogen.

Professor Mike Charlton said: "The existence of antimatter is well established in physics, and it is buried deep in the heart of some of the most successful theories ever developed. But we have yet to answer a central question of why didn't matter and antimatter, which it is believed were created in equal amounts when the Big Bang started the Universe, mutually self-annihilate?

"We also have yet to address why there is any matter left in the Universe at all. This conundrum is one of the central open questions in fundamental science, and one way to search for the answer is to bring the power of precision atomic physics to bear upon antimatter."

It has long been established that any excited atom will reach its lowest state by emitting photons, and the spectrum of light and microwaves emitted from them represents a kind of atomic fingerprint and it is a unique identifier. The most familiar everyday example is the orange of the sodium streetlights.

Hydrogen has its own spectrum and, as the simplest and most abundant atom in the Universe, it holds a special place in physics. The properties of the hydrogen atom are known with high accuracy. The one looked at in this paper concerns the so-called hyperfine splitting, which in the case of hydrogen has been determined with a precision of one part in ten trillion. This transition is used these days in modern navigation and geo-positioning.

The team have made antihydrogen by replacing the proton nucleus of the ordinary atom by an antiproton, while the electron has been substituted by a positron. Last year, in ground-breaking work published in Nature, the team used UV light to detect the so-called 1S-2S transition between positron energy levels. Now, the team has used microwaves to flip the spin of the positron. This resulted not only in the first precise determination of the antihydrogen hyperfine splitting, but also the first antimatter transition line shape, a plot of the spin flip probability versus the microwave frequency. If there is a difference between matter and antimatter, it could be found in tiny differences between this line shape in hydrogen and antihydrogen.

The Swansea team are:

Academic: Professor Mike Charlton, Dr Stefan Eriksson, Dr Aled Isaac, Professor Niels Madsen, Professor Dirk Peter van der Werf
Research Fellows: Dr Christopher Baker and Dr Dan Maxwell
Post-Graduate students: Steven Armstrong Jones and Muhammed Sameed

-end-



Swansea University

Related Hydrogen Articles:

Paving the way for hydrogen fuel cells
The hype around hydrogen fuel cells has died down, but scientists have continued to pursue new technologies that could enable such devices to gain a firmer foothold.
Keeping the hydrogen coming
A coating of molybdenum improves the efficiency of catalysts for producing hydrogen.
Hydrogen bonds directly detected for the first time
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope.
Argon is not the 'dope' for metallic hydrogen
Hydrogen is both the simplest and the most-abundant element in the universe, so studying it can teach scientists about the essence of matter.
Metallic hydrogen, once theory, becomes reality
Nearly a century after it was theorized, Harvard scientists have succeeded in creating metallic hydrogen.
From theory to reality: The creation of metallic hydrogen
For more than 80 years, it has been predicted that hydrogen will adopt metallic properties under certain conditions, and now researchers have successfully demonstrated this phenomenon.
Artificial leaf goes more efficient for hydrogen generation
A new study, affiliated with Ulsan National Institute of Science and Technology has introduced a new artificial leaf that generates hydrogen, using the power of the Sun to mimic underwater photosynthesis.
Hydrogen from sunlight -- but as a dark reaction
The storage of photogenerated electric energy and its release on demand are still among the main obstacles in artificial photosynthesis.
New process produces hydrogen at much lower temperature
Waseda University researchers have developed a new method for producing hydrogen, which is fast, irreversible, and takes place at much lower temperature using less energy.
Hydrogen in your pocket? New plastic for carrying and storing hydrogen
A Waseda University research group has developed a polymer which can store hydrogen in a light, compact and flexible sheet, and is safe to touch even when filled with hydrogen gas.

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: Radiolab

Oliver Sipple
One morning, Oliver Sipple went out for a walk. A couple hours later, to his own surprise, he saved the life of the President of the United States. But in the days that followed, Sipple's split-second act of heroism turned into a rationale for making his personal life into political opportunity. What happens next makes us wonder what a moment, or a movement, or a whole society can demand of one person. And how much is too much?
Now Playing: TED Radio Hour

Future Consequences
From data collection to gene editing to AI, what we once considered science fiction is now becoming reality. This hour, TED speakers explore the future consequences of our present actions. Guests include designer Anab Jain, futurist Juan Enriquez, biologist Paul Knoepfler, and neuroscientist and philosopher Sam Harris.