|Ping! In this event, two W bosons collide and then decay into particles called muons (red) while the quarks that emitted the W’s produce sprays of other particles (yellow).|
Ever wonder what particle physicists would have done had the Higgs boson not existed? Even before they fired up the atom smasher that 2 years ago blasted out the Higgs—the $5.5 billion Large Hadron Collider (LHC) at the European particle physics lab, CERN, near Geneva, Switzerland—researchers said that if they didn't find that coveted quarry, it wouldn't be a total disaster. If there were no Higgs, they said, then a particular ordinary particle interaction should instead go haywire and hint at whatever nature was doing to get by without the Higgs. Now, physicists at the LHC have spotted the rare interaction in that "no-lose" theorem, which is known as WW scattering.
"I am thrilled," says Barbara Jäger, a theorist at the University of Tübingen in Germany who was not involved in the work. Of course, now that physicists know the Higgs exists, they don't expect WW scattering to go bonkers. But it could still play an important role in the hunt for new physics, as scientists look for deviations from the predictions of the field’s prevailing standard model. That approach would complement studies of the Higgs itself, Jäger says.
The Higgs boson is key to physicists' explanation of how all elementary particles—such as electrons and the quarks that make up protons and neutrons—get their masses. Theorists assume that otherwise massless particles interact with a quantum field a bit like an electric field that consists of Higgs bosons lurking "virtually" in the vacuum. Those interactions give each type of particle a certain amount of energy and, thanks to Einstein's famous equation E = mc2, mass.
Had there been no Higgs boson, this observation would have been the bomb, Adrian Cho