Professor Higgs wipes a tear from his eye as fellow scientists find his 'God particle' on 'momentous day for science' - 40 years after he predicted its existence

Discovery of particle is most important in physics in decades

Leading physicists watch announcement at CERN in Switzerland

End of 40-year quest for 'missing' particle

Last jigsaw piece that proves our view of universe is right

'God Particle' gives particles that make up atoms their mass

Prof Higgs, 83: 'I had no idea this would happen in my lifetime'



The search for the 'God particle' is over.



Almost half a century after the existence of the Higgs boson – the particle that holds the universe together and gives it substance – was predicted, jubilant scientists announced that they appear to have found it.



Rolf Heuer, director-general of Cern, the home of the Large Hadron Collider, told a packed auditorium: 'As a layman, I would say we have it.'



He predicted the discovery will shed light on other mysteries of the universe and added: 'We have reached a milestone in our understanding of nature.'

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Professor Higgs, 83, wiped a tear from his eye as the findings were announced in 2012. He later said: 'It's really an incredible thing that it's happened in my lifetime'

Two high-energy photons collide. Their energy (the red lines) is measured in by an 'electromagnetic calorimeter'. The yellow lines are the measured tracks of other particles produced in the collision. The pale blue volume shows the track through which the particles are sent

Others compared the significance of the sighting to the first moon landing and to Christopher Columbus discovering America.



Newcastle-born Professor Peter Higgs, who dreamed up the concept of the particle that now bears his name while walking in the Scottish Highlands in 1964, was present at the announcement and wiped a tear from his eye.



He said: 'I never expected this to happen in my lifetime and shall be asking my family to put some champagne in the fridge.'



Stephen Hawking, who had bet $100 (£64) that the Higgs boson would never be found, said: 'This is an important result and should earn Peter Higgs the Nobel prize.'



David Cameron offered his congratulations and said he hoped the breakthrough would inspire a generation of researchers to keep Britain at the forefront of scientific discoveries.



The Higgs boson's role is to give the particles that make up atoms their mass. Without this mass, they would zip around the cosmos, unable to bind together to form the atoms that make stars and planets – and people.



Despite its fabled properties, the particle has eluded previous searches and not all scientists believed in its existence.



Joe Incandela, spokesperson of the CMS experiment, announces the discovery of a particle that corresponds to theories of the Higgs boson at CERN today

The particle accelerator: It is within these tubes that physicists are hunting for the 'God' particle

To try to pin it down, scientists at the Large Hadron Collider near Geneva smashed together beams of protons – the 'hearts of atoms' – at close to the speed of light, recreating conditions that existed a fraction of a second after the Big Bang.



If Professor Higgs, of Edinburgh University, was right, a few Higgs bosons should have been created in every trillion collisions.



Although they would rapidly decay, they should have left a recognisable footprint. Yesterday morning, two teams of scientists running independent experiments in secret from each other revealed they had found 'clear signs' of a new particle.



However, the teams, which included hundreds of Britons, stopped short of declaring it the Higgs boson, saying more work is needed to confirm its properties.



WHY THE HIGGS MATTERS - WHAT THE NEW PARTICLE MEANS



The Higgs was proposed in 1964 - it is the last missing piece of the Standard Model, the theory that describes the basic building blocks of the universe. The other 11 particles predicted by the model have been found - the Higgs is the last jigsaw piece.



If the particle was shown not to exist, it would have meant tearing up the Standard Model and going back to the drawing board.

Theory has it that as the universe cooled after the Big Bang, an invisible force known as the Higgs field formed.

This field permeates the cosmos and is made up of countless numbers of tiny particles – or Higgs bosons.As other particles pass through it, they pick up mass.



Any benefits in the wider world from the discovery of the Higgs boson will be long term, but they could be in fields as diverse as medicine, computing and manufacturing.



Experts compare the search for the Higgs boson to the discovery of the electron.



The idea of the electron – a subatomic particle – was first floated in 1838, but its presence was not confirmed for another 60 years.



A century on, the electron’s existence underpins modern science. Our understanding of it is critical to the development of technology from television and CDs to radiotherapy for cancer patients.

Others were not so reticent. Jim Al-Khalili, professor of physics at the University of Surrey, said: 'After all the hype and speculation, after decades of designing the world's most ambitious experiment and months of careful checking of data, today is the pay-off.



'The Higgs really does exist. Nobel prizes all round please.'



Professor Themis Bowcock, head of particle physics at Liverpool University, said: 'Very few scientists would argue privately that this is not a Higgs particle.



'Half a century after it was first proposed, and after a monumental effort by generations of physicists around the world, the discovery of the Higgs represents a major breakthrough in our fundamental understanding of nature.



'For physicists, this is the equivalent of Columbus discovering America.'



One of the reasons for the caution at Cern is that while the new particle has so far behaved liked the elusive Higgs boson it is lighter than expected.



This opens up the possibility of there being more than one Higgs boson and could lead to a new understanding of dark matter, the mysterious substance thought to make up a quarter of the universe.



Professor Tejinder Virdee, of Imperial College London, who helped lead one of the two teams of scientists behind the discovery, said: 'This breaks the way to looking at a new vista in physics. It is a very exciting moment.'

Professor John Womersley. chief executive of the Science and technology Facilities Council, said: 'They have discovered a particle consistent with the Higgs boson. Discovery is the important word. That is confirmed. It's a momentous day for science.'

'This is indeed a new particle,' said lab spokesman Joe Incandela.

'This is something that may in the end be one of the biggest discoveries or observations of any new phenomena that we’ve had in our field in the last 30 or 40 years,' said Incandela.



The discovery fills in the last gap in the 'standard model' of physics - proving Einstein right, and possibly leading to new technologies built on our understanding of the workings of the atom.



MASTER OF THE UNIVERSE: THE QUIET MAN WHO DREAMT UP THE 'GOD PARTICLE' WHILE WALKING IN THE HIGHLANDS



Peter Higgs in the Sixties. The scientist dreamed up the idea of the Higgs boson while walking in the Cairngorms in 1964 Until recently, Professor Peter Higgs was as unknown to most of the world as the famous particle that bears his name. Today the quiet physicist, now retired from the University of Edinburgh, is fast becoming a global celebrity as creator of the theory behind the ‘God particle’.

Prof Higgs, 83, has been waiting since 1964 for science to catch up with his ideas about the Higgs boson.

It was in that year he dreamed up the concept in a moment of inspiration while walking in the Cairngorms.

Two scientific papers followed, the second of which was initially rejected and then finally published in the respected journal Physical Review Letters.

Prof Higgs's groundbreaking proposal was that particles acquire mass by interacting with an all-pervading field spread throughout the universe. The more they interact, the more massive and heavy they become.

A ‘boson’ particle was needed to carry and transmit the effect of the field - the Higgs boson.

Peter Higgs was born in Newcastle in 1929, the son of a BBC sound engineer.

After his family moved to Bristol, he proved a brilliant pupil at Cotham Grammar School before going on to read theoretical physics at King's College London.

He was awarded first class honours in 1950, and after failing to secure a lectureship at King's College, set off for Scotland. In 2006, he retired from the University of Edinburgh, assuming the title of emeritus professor.

Never one to blow his own trumpet, Prof Higgs is described by friends and colleagues as ‘very unassuming’ and shy. Some believe his retiring nature might even have held back his career. Now, despite his best efforts to keep a low profile, the spotlight is turning on him.



British physicist Peter Higgs (right) is welcomed by European Organization for Nuclear Research (CERN) director-general Rolf-Dieter Heuer (left)

British physicist Peter Higgs arrives for the conference near Geneva

In December last year scientists at the Large Hadron Collider (LHC) - the 'Big Bang' particle accelerator which recreates conditions a billionth of a second after the birth of the universe - revealed they had caught a first tantalising glimpse of the Higgs.



Since then they have sifted through vast quantities of data from innumerable high energy collisions in an effort to reduce the odds of being wrong.

A statistical standard of proof known as ‘five sigma’ is the ultimate confirmation of a discovery.



'We observe in our data clear signs of a new particle, at the level of 5 sigma,' said ATLAS experiment spokesperson Fabiola Gianotti, ‘but a little more time is needed to prepare these results for publication.'

'The results are preliminary but the 5 sigma signal at around 125 GeV we’re seeing is dramatic. This is indeed a new particle. We know it must be a boson and it’s the heaviest boson ever found,' said CMS experiment spokesperson Joe Incandela.



'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.'

Inside: The giant project is the most enormous piece of scientific apparatus ever constructed, and is buried 100m beneath the ground

An aerial view of the Swiss-French border, indicating the route of the Large Hadron Collider

GOD PARTICLE: KEY TO THE COSMOS

The Higgs boson is – or was – a key missing piece in the jigsaw for physicists in trying to understand how the universe works. Its discovery will allow them to shed new light on the dawn of time and how we came to be here. Scientists believe that a fraction of a second after the Big Bang that gave birth to the universe, an invisible energy field called the Higgs field formed. This has been described as a kind of ‘cosmic treacle’ across the universe. As particles passed through it, they picked up mass, giving them size and shape and allowing them to form the atoms that make up you, everything around you and everything in the universe. This was the theory proposed in 1964 by former grammar school boy Professor Higgs that has now apparently been confirmed. Without the Higgs field particles would simply whizz around space in the same way as light does. A boson is a type of sub-atomic particle. Every energy field has a specific particle that governs its interaction with what’s around it. What yesterday’s news means for the man in the street is unclear but it could lead to discoveries in fields such as medicine, computing and electronics. For physicists it could shed light on other mysteries of the universe.

'It’s hard not to get excited by these results,' said CERN Research Director Sergio Bertolucci. '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.'

Prof Higgs, who first postulated the theory more than 40 years ago, told the BBC: 'I'm rather surprised that it happened in my lifetime - I certainly had no idea it would happen in my lifetime at the beginning, more than 40 years ago, because at the beginning people had no idea about where to look for it, so it's really amazing for me to find out that it's really enough... for a discovery claim.

'I think it shows amazing dedication by the young people involved with these colossal collaborations to persist in this way, on what is a really a very difficult task. I congratulate them.'

At the LHC, scientists shoot two beams of protons - the 'hearts' of atoms - at each other round 27 kilometres of circular tunnels at almost the speed of light.



When the protons smash together the enormous energies involved cause them to decay into an array of more fundamental particles. These may then decay further into yet more particles.



Physicists needed the Higgs to plug a gaping hole in the 'Standard Model', the theory that explains all the particles, forces and interactions making up the universe.



So far nothing has been observed to account for mass, and the fact that some particles weigh more than others.



According to the theory, the Higgs boson is the emissary of an all-pervading 'Higgs field' that gives matter mass. The more particles interact with the field, the more massive they become and the heavier they are.

A model of the Large Hadron Collider (LHC) tunnel. To confirm the Higgs boson theory scientists at the Collider smashed together beams of protons at close to the speed of light, recreating conditions that existed a fraction of a second after the Big Bang

A Standard Model universe without the Higgs boson could not exist. Everything would behave as light does, floating freely and not combining with anything else. There would be no atoms, made from conglomerations of protons, neutrons and electrons, no ordinary matter, and no us.



Finding no evidence of the Higgs would mean tearing up the Standard Model and going back to the drawing board with a completely new set of theories.'

BRITISH SCIENTISTS CONGRATULATE THE CERN TEAM

'For physicists, this is the equivalent of Columbus discovering America.'



- Prof Themis Bowcock, University of Liverpool British experts queued to heap praise on the discovery of a new sub-atomic particle bearing the hallmarks of the Higgs boson. Professor Valentin Khoze, director of Durham University's Institute for Particle Physics Phenomenology (IPPP), said: 'The mounting evidence that Higgs bosons have been produced and detected at the Large Hadron Collider experiment at Cern is a triumph for particle physics.

'Without the Higgs particle, other particles, such as electrons and quarks, would be massless and the Universe would not be what it is.

'Now, with the amazing results from the LHC, we are finally finding growing experimental evidence that the Higgs really exists.

'The second part of the story about the Higgs particle is even more exciting as it provides us with a window to new physics - a tool for the exploration of the truly unknown.'

Professor Jordan Nash, head of high energy physics at Imperial College London, said: 'This is a fantastic result.

'We are all thrilled to be a part of this discovery and are looking forward with anticipation to studying this new particle and whatever surprises its behaviour may have in store for us.'

Professor Jerome Gauntlett, head of theoretical physics at Imperial College London, said: 'The discovery of the Higgs boson is a truly great moment for science.

'Its origins go back to the 1960s with enormous contributions made by Peter Higgs in Edinburgh and by Tom Kibble and Nobel Laureate Abdus Salam at Imperial.

'It is fantastic moment for British science that 50 years later on we have received such dramatic confirmation of their profound ideas. Like all great discoveries, more detailed studies of the Higgs are likely to have a huge impact on future fundamental scientific inquiry.

'I expect that they will illuminate the nature of the mysterious Dark Matter that pervades the universe, whether or not there are extra dimensions in addition to the three space dimensions that we observe, and ultimately how to unify the Standard Model of Particle Physics with Einstein's Theory of Gravity.' British physicist Peter Higgs (L) talks to Fabiola Gianotti, ATLAS experiment spokesperson, next to CERN Director general Rolf Heuer after the news conference Professor Paul Dauncey, Professor of Particle Physics at Imperial College London said: 'This is a major breakthrough for our understanding of the Universe.

'If this new particle is what we think it is, then it is a completely new type of particle never seen before. We can think of it as the final piece of the puzzle, completing what is considered to be the 'standard' theory. 'But no-one thinks that's really the end of the story, so it might also be the beginning of a new chapter in physics, the first step to a more fundamental view of how everything came to exist. That's why physicists are excited; we just don't know where this will lead.' Professor Sir Timothy O'Shea, Principal of the University of Edinburgh, said: 'We are delighted at this significant development in the search for the Higgs boson, and congratulate Professor Peter Higgs on this. 'This particle is integral to our understanding of the physical world and evidence of its existence is a testament to Professor Higgs and to all the scientists who are working to uncover it.

'Professor Higgs has inspired many colleagues and students over the years, some of whom have also gone on to become involved in the Large Hadron Collider experiments. His legacy will continue to inspire future generations of physicists, at Edinburgh and beyond.' Participants applaud after the presentation results during a scientific seminar to deliver the latest update in the search for the Higgs boson Prof Stefan Soldner-Rembold, Professor of Particle Physics at the University of Manchester, said: 'Today we have witnessed a discovery which gives unique insight into our understanding of the universe and the origin of the masses of fundamental particles.

'There is no doubt that the Higgs particle exists and we now have to understand its properties and whether it behaves exactly as predicted by theory.'

Professor Dave Charlton, deputy spokesperson for the Atlas experiment at the University of Birmingham's School of Physics and Astronomy, said: 'Many people have been working night and day to analyse the fresh data from the LHC which has been pouring in this year, which has allowed us to reveal these exciting preliminary results today.

'The tantalising hints we saw in December are repeated and strengthened in the new Atlas data, so we're now quite confident that we're seeing a new particle.

'Finding out if it's got all the properties of the Standard Model's Higgs boson will need a lot more data and painstaking work. We're now opening a new chapter of fundamental physics, as the LHC was designed to do.'

Prof Themis Bowcock, head of particle physics at the University of Liverpool, who has worked on the LHC, said: 'This is cast-iron proof that a new particle has been discovered. It looks like the Higgs.

'For physicists the dice are definitely now loaded in favour of a discovery. Based on the Cern results alone there appears to be less than one chance in a million that this is fake, which is roughly the same probability as flipping a coin heads-up 21 times in a row. Very few physicists would privately argue that this is not a Higgs particle.

'Half a century after it was first proposed, and after a monumental effort by generations of physicists around the world, the discovery of the Higgs represents a major breakthrough in our fundamental understanding of nature. 'For physicists, this is the equivalent of Columbus discovering America.'



VIDEO: Prof Higgs makes rare public appearance at press conference



