Alpha Collaboration scientists claim precise measurement for space's antimatter

CERN-led Alpha Collaboration has revealed its latest big finding

A team of European scientists claim that it has generated the most "precise" and "direct" measurement of antimatter.

The Alpha Collaboration, which is based at the European Organization for Nuclear Research (CERN) and involves academic and other institutions from across the world, has spent three decades exploring space to examine antimatter.

In particular, the Alpha Collaboration has been trying to find the essential differences between matter and antimatter.

Now, CERN has published an article in the academic journal Nature detailing this ongoing research. It said the research "opens a completely new era of high-precision tests between matter and antimatter".

To develop a better insight into antimatter, the team has focused much of its research on comparing the similarities between hydrogen and antihydrogen atoms.

[Research could] shed light on why the universe is made up almost entirely of matter, even though equal amounts of antimatter should have been created in the Big Bang

"Its spectrum is characterised by well-known spectral lines at certain wavelengths, corresponding to the emission of photons of a certain frequency or colour when electrons jump between different orbits," explained the research group.

"Measurements of the hydrogen spectrum agree with theoretical predictions at the level of a few parts in a quadrillion (10¹⁵) - a stunning achievement that antimatter researchers have long sought to match for antihydrogen."

The researchers explained that by comparing the measurements of these atoms, it is possible to test a theory called the charge-parity-time (CPT) invariance.

This can "shed light on why the universe is made up almost entirely of matter, even though equal amounts of antimatter should have been created in the Big Bang," they claimed.

However, it has been more challenging to produce and trap antihydrogen atoms. As a workaround, the ALPHA team has been using a special laser machine called the Antiproton Decelerator (AD).

In the latest part of this test, the researchers wanted to accelerate their antihydrogen spectroscopy activities by "using not just one but several detuned laser frequencies". They combined these with 1S-2S transition frequency in hydrogen.

The researchers said they were then able to "measure the spectral shape, or spread in colours, of the 1S-2S antihydrogen transition and get a more precise measurement of its frequency".

Professor Jeffrey Hangst of the Institut for Fysik og Astronomi in Denmark and a spokesperson for the Alpha Collaboration, said: "The precision achieved in the latest study is the ultimate accomplishment for us. We have been trying to achieve this precision for 30 years and have finally done it.

"This is real laser spectroscopy with antimatter, and the matter community will take notice. We are realising the whole promise of CERN's anti-proton decelerator (AD) facility; it's a paradigm change."