Neutrino particle 'flips to all flavours'

An important breakthrough may be imminent in the study of neutrinos.

The multinational T2K project in Japan says it has seen indications in its data that these elementary particles can flip to any of their three types.

The results are provisional because experiments had to be suspended in the wake of the Tohoku earthquake in March.

But if confirmed, they would open the door to further research on where the matter in the Universe came from.

Specifically, such studies would ask why the cosmos is composed of normal matter rather than its opposite - antimatter - which theorists say must have been created in equal amounts at the Big Bang.

"It's a step on the road," explained Professor Dave Wark, of Imperial College London and the STFC's Rutherford Appleton Laboratory, which leads the UK involvement in T2K.

"We want to address this asymmetry, but first we have to show that the different 'flavours' of neutrinos can spontaneously change into each other - something we call 'neutrino oscillation'. So far, our experiments have been very positive," he told BBC News.

Detecting 'ghosts'

Neutrinos are among the fundamental building blocks of matter. They swarm all about us.

The Sun, for example, releases them in huge quantities when it fuses hydrogen to make helium - the raw nuclear process at its core.

They are, however, very difficult to study because they interact so weakly with normal matter. Hence, their nickname - "ghost particles".

Nonetheless, scientists have been able to discern three flavours - electron neutrinos, muon neutrinos, and tau neutrinos.

Previous research has characterised two forms of oscillations.

The T2K experiment has now seen hints for a third transformation - that of a muon neutrino turning into an electron neutrino.