'God particle' to be confirmed soon

Dubbed the 'Big Bang machine', the LHC was built at a cost of around £2.6 billion to recreate conditions a fraction of a second after the birth of the universe (Reuters)

Confirmation that scientists have found the Higgs boson, the greatest trophy in particle physics, could come "very soon" in the New Year, it was claimed today.

atest results from the Large Hadron Collider (LHC) show "strong hints" of the subatomic particle which is believed to explain the mystery of mass.

Dubbed the "God Particle", the Higgs boson is the last missing piece in the leading theory - known as the Standard Model - that describes how particles and forces interact to make the world we see around us.

Scientists have been looking for the Higgs by smashing protons, the "hearts" of atoms, together at enormous energies in the LHC.

The £4 billion particle accelerator, which weighs more than 38,000 tonnes and straddles the Swiss-French border, fills a 27-kilometre circular tunnel sunk 100 metres into the ground.

Four huge detectors have been constructed along the tunnel to take "snapshots" of what happens during the proton collisions.

Excitement mounted today as scientists prepared to release new data from two detectors, Atlas and CMS, which are conducting independent searches for the Higgs boson.

Their findings add up to a "tantalising" indication that the Higgs is out there - while still falling short of the statistical proof necessary to confirm it exists.

Professor Tony Doyle, one of the LHC physicists from the University of Glasgow, who is part of the Atlas team, said: "It's fair to say that strong hints are what we're getting right now. My perspective is that this is our Apollo 10 moment. We've shown we've done everything needed to land on the Moon, or in our case, find the Higgs boson.

"Confirmation should be very soon in the New Year. I absolutely think we'll find the Higgs boson next year."

Within the LHC, two beams of protons are accelerated in opposite directions, reaching velocities of 99.99% of the speed of light. Each beam packs as much energy as a Eurostar train travelling at 150 kilometres per hour.

In particle physics, mass can be expressed as energy, in accordance with Einstein's famous law E=MC2.

The scientists know that if the Higgs exists it will lie somewhere within a narrow energy band of between around 115 and 130 GeV (gigaelectronvolts). It is here that they have focused their search.

The Higgs, if it exists, is very short lived and cannot be seen directly. But it can be detected from the way it decays into other particles, as predicted by theory. Each of these signature events is described as a "channel".

Atlas and CMS have shown several of the right sort of events at energy levels that could be consistent with the Higgs boson. However, it is not possible to say for sure that they were not the result of random fluctuations .

A release from Cern, the European Organisation for Nuclear Research, which is co-ordinating the search for the Higgs, said "tantalising hints" had emerged from both detectors in the 115-130 GeV mass region, but the evidence was "not yet strong enough to claim a discovery".

CMS experiment spokesperson Professor Guido Tonelli said: "We cannot exclude the presence of the Standard Model Higgs between 115 and 127 GeV because of a modest excess of events in this mass region that appears, quite consistently, in five independent channels.

"The excess is most compatible with a Standard Model Higgs in the vicinity of 124 GeV and below but the statistical significance is not large enough to say anything conclusive. As of today what we see is consistent either with a background fluctuation or with the presence of the boson. Refined analyses and additional data delivered in 2012 by this magnificent machine will definitely give an answer."

Two of the characteristic ways the Higgs can decay is into either two Z boson particles or two photons.

Both of these were observed in the Atlas detector at an energy level of 126 GeV, said Prof Doyle.

However, the number of events was not large enough to discount statistical error.

"Based on what we have already seen, the indications are that the Higgs or something like it exists at around this mass range," Prof Doyle added.

"We've ruled out almost everywhere the Higgs might be apart from this very small 15 GeV window."

Professor Themis Bowcock, head of particle physics at the University of Liverpool, whose group worked on the construction of Atlas, said: "The standard model relies on a particle called the Higgs boson which interacts with other particles making some very heavy whilst leaving others light. This shapes the Universe we know today. However to date no one has found direct evidence of the Higgs. The Atlas and CMS experiments at the LHC have come as close as anyone to observing the Higgs and now both have presented small but significant signals.

"It is possible that each observation is simply a statistical fluke, a fluctuation in the background, mimicking a Higgs signal. But the fact that Atlas and CMS independently agree on the possible Higgs mass substantially increases the overall significance of the results.

"If the Higgs observation is confirmed, through analysis of data to be collected next year, this really will be one of the discoveries of the century. Physicists will have uncovered a keystone in the makeup of the Universe - one whose influence we see and feel every day of our lives."

Claire Shepherd-Themistocleus, head of the CMS Group at the Rutherford Appleton Laboratory in Didcot, Oxfordshire, said: "We are homing in on the Higgs. We have had hints today of what its mass might be and the excitement of scientists is palpable.

"Whether this is ultimately confirmed or we finally rule out a low mass Higgs boson, we are on the verge of a major change in our understanding of the fundamental nature of matter."

PA