2012/12/31 by ATLAS Collaboration · 1 citation
Physics and Astronomy · #hep-ex
paper · pdf · doi:10.1103/physrevlett.110.182302
published as Phys. Rev. Lett. 110, 182302 (2013) · 5 pages plus author list (18 pages total), 4 figures, submitted to Physical Review Letter. Additional auxiliary plots can be found at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2012-13/. Change to reference w.r.t v1. Revision corresponds to published version
arxiv created 2013/04/19 · arxiv updated 2013/06/11
Two-particle correlations in relative azimuthal angle (Delta-phi) and pseudorapidity (Delta-eta) are measured in sqrt(sNN) = 5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 mub-1 of data as a function of pT and the transverse energy (SumET) summed over 3.1 < eta < 4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Delta-eta|<5) near-side (Delta-phi ~ 0) correlation that grows rapidly with increasing SumET. A long-range away-side (Delta-phi ~ pi) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small SumET, is found to match the near-side correlation in magnitude, shape (in Delta-eta and Delta-phi) and SumET dependence. The resultant Delta-phi correlation is approximately symmetric about pi/2, and is consistent with a cos(2Delta-phi) modulation for all SumET ranges and particle pT. The amplitude of this modulation is comparable in magnitude and pT dependence to similar modulations observed in heavy-ion collisions, suggestive of final-state collective effects in high multiplicity events.