Scientists including those based at Harwell Oxford science centre today hailed the "momentous" discovery of what appears to be the "God particle".
Teams at the Large Hadron Collider (LHC), the £2.6 billion atom-smashing machine near Geneva, say they have found a new sub-atomic Higgs boson particle that gives matter mass and holds together the fabric of the universe.
Observations carried out so far show it looks and acts like the long-sought particle that has eluded them for 50 years.
Today's announcement came at a seminar at the Geneva headquarters of Cern, the European Organisation for Nuclear Research, where a tense audience heard the latest progress report from the LHC.
Speaking at a London briefing with a live link to the seminar, Prof John Womersley, chief executive of the Science and Technology Research Council, who is based at the Rutherford Appleton Laboratory at Harwell Oxford, 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."
The LHC, the largest scientific instrument ever built, lies in an underground tunnel with a circumference of 17 miles, which straddles the French-Swiss border near Geneva.
Scientists confirmed that two of the LHC's giant detectors, CMS and Atlas, had delivered results in the search for the particle that reached the definitive "five sigma" level of proof.
Protons, the "hearts" of atoms, are fired around the ring in opposite directions at almost the speed of light.
When they smash together, huge amounts of energy are converted into mass and new particles are created.
Higgs bosons emerge but only fleetingly — for less than a trillionth of a second — before decaying.