Particles and anti-particles annihilate each other in a small flash of energy when they collide.

At the moment of the big bang, nearly 14 billion years ago, matter and anti-matter are thought to have existed in equal quantities. If that balance had persisted, the observable Universe we inhabit would never have come into being.

For unknown reasons — and fortunately for us — Nature seemed to have a slight preference for matter, and today anti-matter is rare.

This asymmetry remains one of the greatest riddles in particle physics.

But ongoing low-energy experiments with hydrogen atoms could be a key step toward solving it.

‘We can keep the antihydrogen atoms trapped for 1,000 seconds. This is long enough to begin to study them — even with the small number that we can catch so far,’ said Jeffrey Hangst, spokesman for the ALPHA team conducting the tests at the European Organisation for Nuclear Research (CERN) in Geneva.

In the study, published in the journal Nature Physics, researchers report trapping some 300 antiatoms.

Scientists used CERN’s high-energy accelerator to create the antihydrogen atoms, and then chilled them to near-zero temperatures.

The aim is to use laser and microwave spectroscopy to compare the immobilised particles to their hydrogen counterparts.

The same team succeeded […]