Searching for the Higgs boson, the particle predicted to exist as a consequence of the Higgs field – which matter interacts with and gets its mass from – was like searching for a single needle in a gigantic haystack. Only by surveying the data produced by particle collisions time and time again – each time, another search for that needle – did researchers find a mass signal that correlated with that expected for the predicted particle. Scientists couldn’t simply look for the needle – they had to look at the masses of fragments produced by particle collisions to see if anything had a mass that was roughly what they would expect a needle to have. The Higgs boson was predicted on paper by particle physicist Peter Higgs in the 1960s, but only after careful sifting through petabytes of data produced by collisions in the large hadron collider at CERN was something confirmed to have been spotted in the first half of 2012.
Two independent experiments, ATLAS and CMS, both confirmed the existence of a particle with the mass expected for a Higgs Boson (about 126.5GeV) at 5 sigma – meaning that there was less than a 1/3,000,000 chance it was a false positive. It is also indicative of just how much data needed to be processed, about 27 terabytes of raw data per day, just to get a statistically significant result. Processing all that data wouldn’t have been possible without the grid.
The importance of the grid in the story of the grid was highlighted during the announcement made on 4 July that year. After the CMS and ATLAS results were announced, Director General at CERN, Rolf Hauer said: “It's been a global effort, a global success. It has only been possible because of the extraordinary achievements of the experiments, infrastructure, and the grid computing. We have a discovery; we have a new particle consistent with the Higgs boson. It’s a historic milestone today, but we are only at the beginning. We can all be proud and it has global implications for the future. I think we can be very optimistic."