“I only remember the joy. I remember everyone being so happy. And what surprised me [was] how interested everyone was, it seemed like the whole world was celebrating us,” he said. Now, as the Large Hadron Collider (LHC) – the monster proton smasher at the European particle laboratory Cern – prepares to begin its third data-gathering period on Tuesday, experts hope to uncover further secrets of the universe’s fundamental building blocks. Bortoletto, now head of particle physics at the University of Oxford and part of the team that discovered the Higgs boson, said her main memory of the events a decade ago was the moment two weeks before the announcement when the researchers unblinded the analysis of the data. and saw clear signs of the boson. “Still, I think [about] at that moment, put butterflies in my stomach,” he said. “It was incredible. It is truly a unique moment in a scientist’s life.” The media frenzy when the discovery was announced was enormous, with newspapers, radio and television focusing on a particle as fleeting as it was important. Called the ‘God particle’ and named after the physicist Peter Higgs, the Higgs boson is the signature particle of the Higgs field – an invisible energy field that permeates the universe. In short, it is the interaction of fundamental particles with this field, interactions originally thought to have occurred shortly after the Big Bang as the universe expanded and cooled, that gives them mass. The existence of the Higgs boson was predicted by the Standard Model, a basic theory that explains three of the four fundamental forces of nature, but scientists didn’t find the crucial clues until experiments at the LHC. Thanks to the discovery of the Higgs boson, scientists can now explain a number of phenomena: from why electrons have mass and therefore can form a cloud around a nucleus, which creates atoms. about why a neutron is more massive than a proton, and therefore why the former decays but the latter is stable. “The Higgs field explains why atoms exist, why we exist. And the fact that we can put it in a context that we think we understand, I think is really cool,” Bortoletto said. But the story is far from over. Since the announcement in 2012 there have been further revelations – including insights into how the Higgs boson is born and decays, and its interactions with heavy particles such as top and bottom quarks. And the work continues apace. Among other efforts, scientists hope to study the interactions between the Higgs boson and muons – fundamental, negatively charged subatomic particles – and explore the coupling of the Higgs boson to itself. “Understanding, for example, the Higgs self-coupling could [help us] understand the form of the Higgs potential and better understand what happened at the beginning of the universe,” Bortoletto said. Key to such work is the third run of the LHC, expected to start on Tuesday. This time the atom smasher will operate at 13.6 trillion electron volts (TeV), up from 13 TeV, with Bortoletto revealing that both the Atlas and CMS experiments are expected to double their data sets. “More data and a little more energy opens up new opportunities,” Bortoletto said. He said scientists will be able to study the Higgs boson in more detail, and the work may also provide new insights into the mass of the W boson. Another fundamental particle, the W boson was at the center of a sensation earlier this year, when researchers at the Collider detector at Fermilab in the US revealed their data that the particle is much more massive than predicted by the standard model. Bortoletto added that there was room for more important discoveries. “There’s a lot of scope in the Higgs field,” he said. “Again, we have a little more energy, we might discover something new, some new particle – we have the opportunity, every time we go higher in energy to maybe discover new physics.”
