Large Hadron Collider restarted in Cern as scientists begin hunt for dark matter

The Large Hadron Collider has been restarted as scientists begin their hunt for dark matter.

Scientists plan to send two high energy particle beams through the LHC's 27 kilometres (16.7 miles) of circular underground tunnels.

Two years ago the LHC team, which includes a number of British physicists, 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 per cent of matter in the universe and binds galaxies together yet whose nature is unknown.

Once both beams are flying around the whole circumference of the giant £3.74 billion machine straddling the Swiss-French border the "restart" will be complete.

Earlier, Frederick Bordry, director for accelerators and technology at Cern, the European Organisation for Nuclear Research, handed out Easter eggs to tense staff in the LHC control room.

Arnaud Marsollier, from Cern, the European Organisation for Nuclear Research in Geneva, which operates the LHC, said: "The LHC 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 LHC after a two year re-fit and upgrade almost doubling its power.

Additional reporting by the Press Association