Giant particle smasher restart

Scientists at the European Organization for Nuclear Research, or CERN, on Sunday shot the first particle beams through the restarted Large Hadron Collider (LHC), after the particle accelerator underwent two years of work to increase its collision capacity.

The LHC - also known as the "Big Bang" collider -, which consists of a 27-kilometer-long (16.8-mile-long) tunnel beneath the Swiss-French border, is being used by researchers to study the "dark universe" - the subatomic particles that make up some 96 percent of matter in the known universe, along with the forces that hold them together.

The collider hit the headlines in 2012 with the discovery of the Higgs Boson, a subatomic particle that confers mass, whose existence had been theorized since 1968 but not confirmed.

The discovery earned the Nobel prize for two of the scientists who had proposed the existence of the particle.

The LHC uses powerful magnets to bend beams of protons coming from opposite directions, thus creating collisions that are monitored by sensors.

The subatomic debris is scanned for unknown kinds of particles and also provides information on coherent forces.

Scientists say the collider has nearly twice its previous energy following the upgrade, which will enable it to produce even more powerful collisions.

The restart was delayed last Saturday following a short-circuit in one of the LHC's magnet circuits.

tj/jil (AFP, AP)