CERN scientists hail probable Higgs boson discovery

Scientists at CERN in Switzerland believe they have discovered a new sub-atomic particle that is consistent with the long-sought after Higgs boson, the so-called 'God' particle that gives matter mass and fills a gap in the Standard Model theory of how the universe works.

The announcement was made in Geneva, home of CERN's Large Hadron Collider particle accelerator. Combined results from two experiments – known as ATLAS and CMS – have been described as sigma 4.9, meaning there is just a one in two million chance that they represent a statistical fluke rather than a true discovery.

Joe Incandela, a spokesman for the CMS experiment, said: "This is indeed a new particle. We know it must be a boson and it's the heaviest boson ever found. The implications are very significant and it is precisely for this reason that we must be extremely diligent in all of our studies and cross-checks."

The preliminary results are based on data collected in 2011 and 2012, CERN said in a statement. The Higgs boson theory was first suggested by British physicist Peter Higgs and five others in the 1960s, and scientists have been searching for the elusive particle ever since. Higgs was among the audience gathered in Geneva to hear the dramatic announcement of what could be one of the greatest scientific discoveries of the century.

CERN director general Rolf Heuer said it was a "milestone" in human understanding. "The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle's properties, and is likely to shed light on other mysteries of our universe."

Research director Sergio Bertolucci added that it was "hard not get excited by these results". He said: "We stated last year that in 2012 we would either find a new Higgs-like particle or exclude the existence of the Standard Model Higgs. With all the necessary caution, it looks to me that we are at a branching point. The observation of this new particle indicates the path for the future towards a more detailed understanding of what we're seeing."

Professor John Womersley, chief executive of the Science and Technology Facilities Council, said: "These results mark a significant breakthrough in our understanding of the fundamental laws that govern the universe." The Higgs boson theory has been described as like an invisible force field and associated particles that give form to all objects in the universe – without which all matter would float freely like light.

Scientist at the LHC, which simulates the conditions immediately after the big bang, first suggested they had made a breakthrough last December. Professor Tom Kibble from Imperial College in London, who was involved in proposing the theory 50 years ago, said: "At the time, Higgs boson did not seem a very significant feature of the theory, but it has become so as the last missing piece of the Standard Model. Its discovery will complete a chapter, but not the story – the model in amazingly successful, but many features remain to be explained."

In its statement CERN said the next step would be to determine the exact nature of the particle, asking: "Are its properties as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? Or is it something more exotic? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4 per cent of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96 per cent of the universe that remains obscure."