LHC to probe early universe in best detail yet
From New Scientist, Nov. 1, 2011
The Large Hadron Collider will spend four weeks probing the conditions of the early universe in better detail than ever before, as it takes a break from the hunt for the Higgs boson.
The LHC's main activity for 2011, colliding pairs of protons, came to an end as scheduled on 30 October. The experiment has now produced about 6 inverse femtobarns of collision data, about three times the total used in the last major analysis searching for the Higgs boson, thought to endow other particles with mass, which was reported in August.
As researchers start analysing the new data, the LHC is switching to colliding lead ions for four weeks, starting on 5 November. These collisions produce pockets of very dense and hot matter, recreating the conditions in the first moments after the big bang.
Lead ion collisions at the LHC last year showed hints of producing a quark-gluon plasma, an exotic state of matter in which quarks – normally bound in pairs or triplets – are able to wander freely. The phenomenon has been observed previously at the Relativistic Heavy Ion Collider in Brookhaven, New York, but the LHC's higher-energy collisions allows higher temperatures to be obtained.