CERN’s Large Hadron Collider Experiments Bring New Insight Into Matter of the Primordial Universe
ScienceDaily (Aug. 13, 2012) — Experiments using heavy ions at CERN’s Large Hadron Collider (LHC) are advancing understanding of the primordial Universe. The ALICE, ATLAS and CMS collaborations have made new measurements of the kind of matter that probably existed in the first instants of the Universe. They will present their latest results at the 2012 Quark Matter conference, which starts August 13 in Washington DC. The new findings are based mainly on the four-week LHC run with lead ions in 2011, during which the experiments collected 20 times more data than in 2010.
Just after the Big Bang, quarks and gluons — basic building blocks of matter — were not confined inside composite particles such as protons and neutrons, as they are today. Instead, they moved freely in a state of matter known as ‘quark-gluon plasma’. Collisions of lead ions in the LHC, the world’s most powerful particle accelerator, recreate for a fleeting moment conditions similar to those of the early Universe. By examining a billion or so of these collisions, the experiments have been able to make more precise measurements of the properties of matter under these extreme conditions.
“The field of heavy-ion physics is crucial for probing the properties of matter in the primordial Universe, one of the key questions of fundamental physics that the LHC and its experiments are designed to address. It illustrates how in addition to the investigation of the recently discovered Higgs-like boson, physicists at the LHC are studying many other important phenomena in both proton-proton and lead-lead collisions,” said CERN Director General Rolf Heuer.
Read more: http://www.sciencedaily.com/releases/2012/08/120813115445.htm