2016/01/08 by STAR Collaboration, L. Adamczyk, J. K. Adkins +328 · 1 citation
Physics and Astronomy · #nucl-ex
paper · pdf · doi:10.1103/physrevlett.116.112302
published as Phys. Rev. Lett. 116, 112302 (2016) · 7 pages, 4 figures, for submission to Phys. Rev. Lett
arxiv created 2016/01/08 · arxiv updated 2016/03/23
We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from √sNN=7.7 GeV to 200 GeV. The third harmonic v32\2\=⟨ cos3(ϕ1-ϕ2)⟩, where ϕ1-ϕ2 is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη= η1-η2. Non-zero \vthree is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity Quark Gluon Plasma (QGP) phase. For sufficiently central collisions, v32\2\ persist down to an energy of 7.7 GeV suggesting that QGP may be created even in these low energy collisions. In peripheral collisions at these low energies however, v32\2\ is consistent with zero. When scaled by pseudorapidity density of charged particle multiplicity per participating nucleon pair, v32\2\ for central collisions shows a minimum near \snn=20 GeV.