Physics – Nuclear Physics – Nuclear Experiment
Scientific paper
2009-08-15
Physics
Nuclear Physics
Nuclear Experiment
9 pages, 7 figures. To appear in the proceedings for 5th International Workshop on Critical Point and Onset of Deconfinement (
Scientific paper
Analysing two-particle azimuthal and pseudorapidity-azimuth correlations of high-pT hadrons, experiments at the RHIC have obtained results - "the double hump", "the ridge" etc. - which provide interesting information about properties of the hot, dense medium produced in central high-energy heavy-ion collisions as well as of its interaction with products of hard scattering. However, not all of the observed effects have been fully explained by theory or models yet; such explanations are hampered in part by the lack of good reference from lower collision energies. In an attempt to further our understanding of angular dihadron correlations NA49 has, as one of the first experiments at the SPS, performed a number of scans of these correlations in Pb+Pb, Si+Si and p+p collisions at sqrt(sNN) = 17.3 GeV, as well as central Pb+Pb collisions at sqrt(sNN) = 12.3, 8.8, 7.6 and 6.3 GeV. Results of these scans have been compared to UrQMD simulations. Our experimental results from two-particle azimuthal correlations show a flattened away-side peak in central Pb+Pb (Au+Au) collisions, only weakly depends on collision energy over the whole investigated energy range - suggesting this effect originates from sources other than jet-medium interactions. This hypothesis is reinforced by good agreement with UrQMD regardless of whether jet production was enabled in the model or not. On the other hand, the amplitude of the near-side peak in central Pb+Pb (Au+Au) collisions drops visibly with decreasing collision energy, flattening out around sqrt(sNN) = 8.8 GeV and turning into a depletion below that energy - possibly an effect related to the onset of deconfinement. Finally, hints of the ridge structure can be observed in pseudorapidity-azimuth correlation functions from central Pb+Pb collisions at sqrt(sNN) = 17.3 GeV.
for the NA49 Collaboration
Szuba Marek
No associations
LandOfFree
Energy Dependance of Azimuthal Correlations (and more) in Nucleus-Nucleus Collisions at the CERN SPS does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Energy Dependance of Azimuthal Correlations (and more) in Nucleus-Nucleus Collisions at the CERN SPS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Energy Dependance of Azimuthal Correlations (and more) in Nucleus-Nucleus Collisions at the CERN SPS will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-75955