The world's largest atom smasher is gearing up for its second three-year run after 16 months of maintenance and upgrades.
The Large Hadron Collider, which was used to discover a long-theorised subatomic particle, is designed to push the proton beam close to the speed of light, whizzing 11,000 times a second around a 17-mile (27-kilometre) tunnel on the Swiss-French border near Geneva. The world's top particle physics lab known by its French acronym CERN said Monday that the $10 billion collider is being improved and is on track to resume early next year at double its former energy level.
Once it restarts, two beams will be fired again within the collider at the same time in opposite directions with the aim of recreating conditions a split second after the Big Bang, which scientists theorize was the massive explosion that created the universe. The next CERN experiments could reveal more about "dark matter," antimatter and possibly hidden dimensions of space and time.
"The machine is coming out of a long sleep after undergoing an important surgical operation," said Frederick Bordry, director for accelerators and technology at the European Organization for Nuclear Research.
During its first run, the particle accelerator was used to discover the subatomic particle known as the Higgs boson, without which particles wouldn't hold together - and there would be no matter. The state-of-the-art accelerator - and teams of thousands of CERN-based scientists - helped Peter Higgs win the Nobel Prize last year by proving his theories right.
"It's effectively a new machine, poised to set us on the path to new discoveries," CERN Director General Rolf Heuer said.
In a breakthrough, researchers at the CERN found the first evidence for the direct decay of the Higgs boson into fermions - a strong indication that the particle discovered in 2012 is the Higgs boson.
The findings confirm that the bosons decay to fermions - a group of particles that includes all leptons and quarks - as predicted by the Standard Model of particle physics.
"This is an enormous breakthrough," said Markus Klute, an assistant professor of physics at Massachusetts Institute of Technology (MIT).
"Now we know that particles like electrons get their mass by coupling to the Higgs field, which is really exciting," said Klute.
In July 2012 researchers from the ATLAS and Compact Muon Solenoid (CMS) experiments at the European Organisation for Nuclear Research (CERN), said they had observed a new particle in the mass region of 125 to 126 gigaelectronvolts (GeV).