Soft probes of p+Pb and Pb+Pb collisions in the ATLAS experiment at the LHC

Hot Quarks 2014: Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions

Radhakrishnan, S.^1

Department of Physics, Stony Brook University, NY, United States^1

关键词: Azimuthal correlations;    Expansion dynamics;    Heavy ion collision;    Higher order harmonics;    Hydrodynamic calculation;    Initial conditions;    Non-linear hydrodynamics;    Selection procedures;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/612/1/012060/pdf
DOI  :  10.1088/1742-6596/612/1/012060

来源: IOP

【 摘 要 】

Collective flow and azimuthal correlation measurements of particles in the pTregion10 GeV provide valuable information in constraining the initial conditions and expansion dynamics of the system produced in heavy-ion collisions. ATLAS collaboration has recently measured correlations between flow harmonics in Pb+Pb collisions at √sNN= 2.76 TeV, using an event-shape selection procedure, and has separated the components arising from linear and non-linear hydrodynamic evolution in higher order harmonics (v4and v5). A brief overview of these results are presented in these proceedings. Recently, azimuthal correlations extending to large pseudorapidity differences ("ridge"), similar to that seen in heavy-ion collisions, was observed in p+Pb collisions at LHC. These proceedings also present a measurement of the Fourier harmonics associated with the ridge correlations (v1to v5) in p+Pb collisions at √sNN= 5.02 TeV by ATLAS collaboration. The results are compared with vnin Pb+Pb collisions at √sNN= 2.76 TeV with similar event multiplicities. Reasonable agreement is observed after accounting for the difference in the average pTof particles produced in the two collision systems, consistent with a recent hydrodynamic calculation.