System size and energy dependence of near-side di-hadron correlations

Collaboration
Oct, 2011
17 pages
Published in:
  • Phys.Rev.C 85 (2012) 014903
e-Print:
Experiments:

Citations per year

2012201520182021202402468
Abstract: (arXiv)
Two-particle azimuthal (Δϕ\Delta\phi) and pseudorapidity (Δη\Delta\eta) correlations using a trigger particle with large transverse momentum (pTp_T) in dd+Au, Cu+Cu and Au+Au collisions at sNN\sqrt{s_{{NN}}} =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both Δϕ\Delta\phi and Δη\Delta\eta, and the ridge, narrow in Δϕ\Delta\phi but broad in Δη\Delta\eta. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated pTp_T. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at sNN\sqrt{s_{{NN}}} = 200 GeV, is also found in Cu+Cu collisions and in collisions at sNN\sqrt{s_{{NN}}} =\xspace 62.4 GeV, but is found to be substantially smaller at sNN\sqrt{s_{{NN}}} =\xspace 62.4 GeV than at sNN\sqrt{s_{{NN}}} = 200 GeV for the same average number of participants (Npart \langle N_{\mathrm{part}}\rangle). Measurements of the ridge are compared to models.
Note:
  • 17 pages, 14 figures, submitted to Phys. Rev. C
  • 24.85.+p
  • 21.65.Qr
  • 25.75.Bh
  • 25.75.Gz
  • hadron hadron: correlation
  • angular correlation
  • transverse momentum: high
  • heavy ion: scattering
  • deuteron
  • gold