The world’s most-wanted particle continues to elude the world’s most powerful particle accelerator. A sign that the elusive Higgs boson doesn’t exist? Not so fast. For now, there are good reasons to assume the Higgs is just hiding.
“It’s never too early to think about it, but it is too early to worry,” says Nobel prize-winner Frank Wilczek of the Massachusetts Institute of Technology.
The still-hypothetical Higgs boson is thought to endow all other particles with mass. Confirming its existence would complete the standard model of physics, the leading theory for how particles and forces interact. Finding the Higgs and pinning down its mass, or ruling out its existence and paving the way for new models, is one of the goals of the Large Hadron Collider at CERN near Geneva, Switzerland.
Since it started smashing protons together in 2009, the LHC has steadily collected data that help rule out various masses for the Higgs from a range of possibilities allowed by the standard model. Combined with earlier results from other accelerators, the latest LHC limits, announced on 22 August at the Lepton-Photon conference in Mumbai, India, mean the Higgs is now restricted to having a mass of between 115 and 145 gigaelectronvolts (GeV), or 122 to 154 times the mass of a proton (mass and energy can be treated interchangeably for particles).