First shot in LHC's nuclear science mission

10 September 2008

Nuclear scientists celebrated the first beam in the world's largest ever particle accelerator today. The Large Hadron Collider promises to reveal more about conditions after the Big Bang than ever known before and even create miniature black holes.


The machine spans the border of Switzerland and France and is primarily composed of twin 27 kilometre loops about 100m below ground. Two preliminary acceleration loops supply packets of protons at near the speed of light to the main loops where they travel in opposite directions. A final sequence of acceleration and synchonisation takes the protons packets to a speed so close to that of light that their masses increase by a factor of 25 compared to that at rest.



Let's get smashed: protons take a tour of the LHC (Image: CERN)


When the packets are made to collide at four experiment points, they strike each other with energies of 14 TeV and break into their constituent parts. Physicists think one such part will be the Higgs boson, predicted by the Standard Model to be the elementary particle that gives mass to all others. Its discovery would be a significant step toward a Grand Unified Theory covering the strong nuclear force, the weak nuclear force and electromagnetism. Only the force of gravity would be left out, but information about the Higgs boson could help understand that too.


Four main experiments will now begin at the LHC, run by scientists from over 100 countries at CERN, the European Centre for Nuclear Research. A detector called Alice will help scientists study quark-gluon plasma, as existed in the instants that followed the Big Bang and the LHCb will search for anti-matter by studying the beauty quark. The Compact Muon Solenoid will look for the Higgs boson, as will the similar Atlas detector that will also keep an eye out for evidence for dark matter, extra dimensions of space and microscopic black holes.


Theory dictates that any black holes created in LHC ought to evaporate due to Hawking radiation before they destroy the world -  and so far this has proven to be correct.