The search for the arcane, theoretical particle known as the Higgs bosonhas drawn on the world’s largest scientific instruments and occupied thousands of researchers over more than two decades. The discovery – or probable discovery – at Cern, the particle physics lab near Geneva, will go down as a triumph of science, engineering and collective hard graft. Now the real work begins.
Months and years of analysis lie ahead to confirm that the particle is the elusive Higgs boson. If so, physicists want to know whether it is the simplest kind of particle put forward in physicists’ theories, or something more unusual – and more exciting.
“It’s clear there’s a great deal more to be done experimentally, even after they announce a discovery,” says Steven Weinberg, a professor of physics at the University of Texas at Austin, who won the Nobel prize in 1979 for work that used the maths behind the Higgs theory to show how two forces of nature, the electromagnetic force that carries light, and the weak force, which drives some kinds of radioactive decay, were one in the early universe.
The Higgs boson appears in a theory first fleshed out in 1964 by Peter Higgs at Edinburgh University and five other physicists. Finding the particle proves there is an energy field that fills the vacuum of the observable universe. It plays the crucial role of giving mass to certain subatomic particles that are the building blocks of matter.
The Higgs field is thought to have switched on a trillionth of a second after the big bang that blasted the universe into existence. Without it, or something to do its job, the structure of the cosmos would be radically different than it is today.
The tough job ahead is working out whether the Higgs particle is the simple, singular particle that underpins what physicists call the Standard Model – a set of equations that describe how all the known particles behave – or something more complex.