The Higgs boson makes the universe stable – just. Coincidence?

 作者:冀绮     |      日期:2019-03-15 05:19:01
Edmon de Haro By Anil Ananthaswamy OUR universe has been around for nearly 14 billion years, but it could vanish in the blink of an eye. That’s because the fabric of space-time might be in a state of precarious stability – what physicists call a false vacuum – and could collapse at any moment, taking us with it. “If a bubble of true vacuum appeared near us in the universe and expanded to include us, we’d all be very, very dead,” says Sean Carroll, a theoretical physicist at the California Institute of Technology in Pasadena. The key to understanding how stable the vacuum is rests with the Higgs boson and its associated field, which pervades all of space-time and gives elementary particles their mass. In July 2012, physicists at the Large Hadron Collider (LHC) in Geneva, Switzerland, finally sighted the Higgs boson and pegged its mass to somewhere between 125 and 127 gigaelectronvolts. Although elementary particles get their masses by interacting with the Higgs field, the mass of the Higgs boson depends on those particles as well. The heaviest of these, the top quark, has the biggest impact on the Higgs mass. And based on the most recent measurements of both their masses, physicists can now use the properties of the Higgs field to deduce the state of the vacuum of space-time. The news isn’t great: our universe could be on the brink. Like a ball rolling down a hill,