To cheers and standing ovations from scientists, the world's biggest atom smasher claimed the discovery of a new subatomic particle Wednesday, calling it "consistent" with the long-sought Higgs boson -- popularly known as the "God particle" -- that helps explain what gives all matter in the universe size and shape.

"We have now found the missing cornerstone of particle physics," Rolf Heuer, director of the European Center for Nuclear Research (CERN), told scientists.

He said the newly discovered subatomic particle is a boson, but he stopped just shy of claiming outright that it is the Higgs boson itself -- an extremely fine distinction.

"As a layman, I think we did it," he told the elated crowd. "We have a discovery. We have observed a new particle that is consistent with a Higgs boson."

The Higgs boson, which until now has been a theoretical particle, is seen as the key to our understanding of why matter has mass, which combines with gravity to give an object weight.