Two beams of particles travelling a whisker below the speed of light were sent flying in opposite directions through the Large Hadron Collider’s 27km of circular underground tunnels straddling the Swiss-French border.
Amid scenes of jubilation in the Large Hadron Collider control room, Professor Rolf Heuer, director general of Cern, the European Organisation for Nuclear Research, said: “Congratulations. Thank you very much everyone ... now the hard work starts.”
The €50bn machine is running at a low “injection” energy of 450 giga-electron volts. In June, the energy level will be ramped up to a record-breaking 13 tera-electron volts) and experiments probing the fundamental building blocks of the universe can begin.
Two years ago the Large Hadron Collider team astounded the world with the discovery of the Higgs boson, an elementary particle that gives other particles mass.
Now the scientists have their sights set on an even more exotic trophy — dark matter, the invisible, undetectable material that makes up 84% of matter in the universe and which binds galaxies together yet whose nature is unknown.
With a beam energy of 13 tera-electron volts — almost twice that which produced the Higgs boson — it is conceivable that the Large Hadron Collider will capture dark matter, marking a leap forward in our understanding of the universe.
Earlier Cern spokesman Arnaud Marsollier said: “The Large Hadron Collider will be running day and night. When we will get results we don’t know. What is important is that we will have collisions at energies we’ve never had before.
“If something interesting appears in this new window we will see it. It might be two months from now or two years, we’re not able to say. It took 50 years to find the Higgs boson and 20 years to build this machine, and it will be running at least until 2035, so we can be patient.”
A technical hitch had delayed the restart of the Large Hadron Collider after a two year refit and upgrade. An electrical short circuit prompted fears that operations could be put back weeks or even months.
However, engineers quickly located the problem — a small piece of metal debris — and removed it.
At a Cern briefing in Geneva last month, British scientist Professor David Charlton, from the University of Birmingham, who heads the Atlas detector team, said: “We’re heading for unexplored territory. It’s going to be a new era for science.”
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