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Title: Charged-Particle Multiplicity Density at Midrapidity in Central Pb-Pb Collisions at sNN = 2.76 TeV

Journal Article · · Physical Review Letters

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nculeon pair {radical}{ovr s{sub NN}} = 2.87 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584{+-}4(stat){+-}76(syst), which corresponds to 8.3{+-}0.4(syst) per participating nucleon pair. This represents an increase of about a facor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at {radical}{ovr s{sub NN}} = 0.2 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
1006479
Journal Information:
Physical Review Letters, Vol. 105, Issue 25; ISSN 0031--9007
Country of Publication:
United States
Language:
English