More studies, however, will be needed to pin down the exact nature of the boson, which is the most massive ever seen, scientist said. "This is indeed a new particle," Joe Incandela, spokesman for the CMS detector said. "The implications are very significant and it is precisely for this reason that we must be extremely diligent in all our studies and cross-checks." The Higgs boson is the last undiscovered particle predicted to exist by the standard model of matter that scientists have been hunting for almost 50 years. It is thought to give all other particles their mass, and some have dubbed it the the God particle because of its importance, to the annoyance of scientists. Researchers will now look to see if the new particle is the one predicted by the standard model.

On the other hand, it could turn out to be and even more exotic version. If this case, it would be a profound discovery, creating a revolution in physics, scientists said. "It could be a gateway to the next phase of exploring the deepest parts of the fabric of the universe," Mr Incandela said. It could be a portal to a exotic world of new particles and new dimensions. Researchers using two huge detectors at the Large Hadron Collider announced the results of their searches at a joint scientific seminar in Geneva and Melbourne, where the International Conference on High Energy Physics is being held.

The two teams had been blinded to each other's data, to avoid influencing their independent analyses. They each found strong evidence for the existence of a particle with a mass of 125-126 gigaelectronvolts – about 130 times the mass of a proton. One of the main reasons the Large Hadron Collider was built deep underground near Geneva was to produce particle collisions with a high enough energy to create the fleeting Higgs boson. For more than two years, beams of protons have been accelerated to almost the speed of light around the 27-kilometre ring deep underground and smashed into each other. This recreated conditions similar to just after the Big Bang, when it was thought the Higgs boson appeared and turned the debris from the explosion into stars and galaxies.

The newly found boson is so short-lived it was only spotted from an excess of the lighter particles it decays into, including two photons. Researchers said properties such as the exact mass, and spin, and the particles it decays into need to be studied to determine the boson's exact nature. Some theories, such as supersymmetry, predict the existence of many new kinds of particles, including a variety of Higgs bosons. It could explain the missing dark matter in the universe. Australian researchers helped design and build parts of the ATLAS detector and helped analyse the results.

In December, the teams using the ATLAS and CMS detectors both said they had seen tantalising "hints" of a Higgs-like bosons. Researchers declare a discovery only when a result has a statistical significance of five sigma, which means a less than one-in-a-million chance of it being just a fluke. Last year's results had a three sigma confidence rating. The new results are 4.9 sigma for the CMS detetcor and five sigma for ATLAS. .