CERN discovers new matter-antimatter asymmetry

Scientists at CERN - the world's biggest atom smasher - have discovered a new matter-antimatter asymmetry in a particle decay that contributes to the apparent lack of antimatter in the universe.
The LHCb collaboration at CERN have reported observing matter-antimatter asymmetry in the decays of the particle known as the 'B0s'. It is only the fourth subatomic particle known to exhibit such behaviour.
Matter and antimatter are thought to have existed in equal amounts at the beginning of the universe, but today the universe appears to be composed essentially of matter.
By studying subtle differences in the behaviour of particle and antiparticles, experiments at the LHC are seeking to cast light on this dominance of matter over antimatter.

Now the LHCb experiment has observed a preference for matter over antimatter known as CP-violation in the decay of neutral 'B0s' particles.
The results are based on the analysis of data collected by the experiment in 2011.

"The discovery of the asymmetric behaviour in the 'B0S' particle comes with a significance of more than 5 sigma - a result that was only possible thanks to the large amount of data provided by the LHC and to the LHCb detector's particle identification capabilities," said Pierluigi Campana, spokesperson of the LHCb collaboration.
"Experiments elsewhere have not been in a position to accumulate a large enough number of 'B0s' decays," said Campana.

Violation of the CP symmetry was first observed at Brookhaven Laboratory in the US in the 1960s in neutral particles called kaons.
About 40 years later, experiments in Japan and the US found similar behaviour in another particle, the 'B0' meson.