BASEL, Switzerland — The Large Hadron Collider restarted Sunday after a two-years of work to make the biggest machine ever built even faster in the hope that it will unspin the secrets of the creation of the universe.
Particles were pushed through the collider’s 17-mile tunnel for the first time since February 2013, said the European Organization for Nuclear Research (CERN).
“There is great joy here,” CERN director general Rolf-Dieter Heuer said at the control centre in Meyrin, near Geneva. “It came off brilliantly.”
The collider, which is under the Swiss-French border, accelerates subatomic particles to nearly the speed of light and smashes them together with the aim of clarifying the theory of the Big Bang, believed to be the moment the universe sprang to life 14 billion years ago.
The renovations at the collider have revved up the already record-breaking machine so the energy of its particle collisions will be nearly doubled, opening up the possibility of discovering new particles and testing unproven theories.
Heuer said CERN expects its collider to be up to full speed in about two months, after the new equipment is calibrated and particle streams intensified.
Part of what the CERN scientists hope to discover is how elementary particles acquire mass.
The collider was restarted nearly three years after experiments there showed that the Higgs boson particle is likely to exist. The particle is believed to be responsible for all mass in the universe. The Higgs boson, nicknamed the “God particle,” was the missing piece in the standard model of physics, which describes how nature’s smallest building blocks interact but could not previously explain why they have mass.
It could also unlock other mysteries left unexplained by the standard model, including dark matter, a form of invisible matter that is believed to make up most of the universe.
CERN researchers said they hope the collider will provide the first concrete evidence for the existence of dark matter, as well as information about its composition.
“The restart with notable higher energy opens up the chance to push forward into unexplored regions and to discover new physics phenomena like dark matter,” said Joachim Mnich, director of particle physics at Germany’s national research center that operates particle accelerators. “All particle physicists involved look towards Geneva with excitement.”
Mnich and the 150 other researchers at his center are among the tens of thousands of scientists taking part worldwide in the CERN experiments.
“We are all excited how quickly now after more than two years of construction that the first particle stream occurred successfully in the accelerator ring,” Heuer said.
But he advised patience about when new discoveries might be announced.
“I am very careful here” about predictions, he said.