Blip flop as tantalising bump in Large Hadron Collider data disappears

It was a result that seemed to herald the discovery of a brand new sub-atomic particle and a clutch of Nobel prizes.

Some suggested that a tantalising bump in data collected by the Large Hadron Collider (LHC) at Cern could be a cousin to the much feted Higgs Boson. Others pondered the possibility that it was a graviton – a particle thought to be involved in the force of gravity. Everyone, it seemed, was intrigued.

While other blips in data had previously had been seen, and dismissed, this one was different: it had been spotted by two teams working on different experiments on the particle smashing ring – Atlas and CMS.

But, eight months later, such hopes have now been dashed. With the collection of much more data, the signal has vanished, and with it both the puzzle and promise of the particle.

In a press conference held at the International Conference on High Energy Physics in Chicago, researchers revealed the results from an analysis of new data, collected since the LHC was switched back on in May.

“What we saw in the 2015 data was a bump which was not hugely statistically significant, but nonetheless there was a bump, a clustering of events at a mass of about 750 GeV,” said David Charlton, professor of particle physics, University of Birmingham and spokesperson for the Atlas Collaboration at Cern. But when the team analysed new data he says, “We see nothing, actually, in the region suggested by last year’s data. We see many events but we see no bump.”

The team working on the CMS experiment, he adds, have also seen no trace of the bump in their new data, suggesting that it was just a statistical fluke.

“If it had been real of course it would have been one of the big projects for this year – to study its properties to try and understand what it is,” said Charlton. “We are not greatly surprised it has gone away, it is just a pity because of course it would have been a fantastic discovery.”

But with the LHC running well and swaths of new data being collected, the teams don’t have too much time to feel downcast.

“We are looking for things like possible explanations for dark matter in the universe, we are looking for possible supersymmetric particles, maybe extra dimensions of space and time,” said Charlton.