As of 2011, the Higgs boson, the quantum of a field that is thought to provide particles with rest masses, remained the only particle of the Standard Model to be verified. On July 4, 2012, physicists working at CERN's Large Hadron Collider announced that they had discovered a new subatomic particle greatly resembling the Higgs boson, a potential key to an understanding of why elementary particles have masses and indeed to the existence of diversity and life in the universe. Rolf-Dieter Heuer, the director general of CERN, said that it was too soon to know for sure whether it is an entirely new particle, which weighs in at 125 billion electron volts – one of the heaviest subatomic particles yet – or, indeed, the elusive particle predicted by the Standard Model, the theory that has ruled physics for the last half-century. It is unknown if this particle is an impostor, a single particle or even the first of many particles yet to be discovered. The latter possibilities are particularly exciting to physicists since they could point the way to new deeper ideas, beyond the Standard Model, about the nature of reality. For now, some physicists are calling it a "Higgslike" particle. Joe Incandela, of the University of California, Santa Barbara, said, "It's something that may, in the end, be one of the biggest observations of any new phenomena in our field in the last 30 or 40 years, going way back to the discovery of quarks, for example." The groups operating the large detectors in the collider said that the likelihood that their signal was a result of a chance fluctuation was less than one chance in 3.5 million, so-called "five sigma," which is the gold standard in physics for a discovery. Michael Turner, a cosmologist at the University of Chicago and the chairman of the physics center board, said