Scientists believe they have captured the elusive "God particle" that gives matter mass and holds the physical fabric of the universe together.
The Science & Technology Facilities council announced that CERN has found a new particle.
It has the properties of Higgs boson but will need verifying to check that it has all the properties.
It's been confirmed by CERN as a "5 sigma" level which means it's officially a discovery.
Professor John Womersley. chief executive of the Science and technology Facilities Council, told reporters at a briefing in London:
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
CERN announcing the discovery of new particle - probably the Higgs boson. There is a one in three million chance they have got it wrong.
David Willetts in Westminster has said that, "Britain has played a major role in this amazing scientific discovery"
It is confirmed that CERN has found a new particle. It will need verifying that it has all the properties of the Higgs boson.
Joe Incandela speaking at CERN said; "this is a preliminary results, but it is very strong."
Scientists gather for the announcement from CERN on the Higgs Boson particle.
The Higgs Boson is a hypothetical particle which is predicted to exist by particle physics. The Higgs boson explains why other particles in the universe have mass, but scientists are not sure if it exists - or if it it exists exactly as they expect.
That is why they have been trying to find the Higgs Boson. At the CERN Large Hadron Collider they hope to create an experiment where it can be measured, the experiment has been likened to re-creating the Big Bang.
In December last year scientists at the Large Hadron Collider (LHC) in Cern revealed they had caught a first tantalising glimpse of the Higgs.
They have since 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" would be the ultimate confirmation of a discovery. In this case, the chances of a mistake are one in a million.
Scientists at Cern, the European Organisation for Nuclear Research in Geneva, are likely to announce a significant step further towards the five sigma goal.
Possibly, they might even be at "four sigma", a hair's-breadth away from having the Higgs in their grasp. In that case the final "discovery" of the Higgs particle will be virtually a foregone conclusion.
We now have more than double the data we had last year. That should be enough to see whether the trends we were seeing in the 2011 data are still there, or whether they have gone away. It's a very exciting time."
The hunt for the fabled "God particle" that lends mass to matter and holds the universe together could soon be over.
Scientists giving a progress report on the search today are expected to say they are almost at the point of confirming the existence of the Higgs boson.
Almost, but not quite. The process of proving the Higgs is real is a gradual one, similar to getting closer to a familiar face seen from afar.