“QGP” models vs. data: summary

• Magnitude of Au+Au suppression  dense partonic medium:

  • <n> = L/≈ 3 – 4 or dNg/dy ~ 1000 or <q0> ~ 3.5 GeV/fm2 or dE/dx ≈ 14 GeV/fm.
• Centrality dependence of Au+Au suppression.
• Dissapeareance of away-side dijet angular correlations.
• Unquenching in d+Au collisions at y = 0.
• "Issues":
• pT dependence of Au+Au suppression  not described in 1st instance:
  • Additional nuclear effects needed to "flatten" LPM [ log(pT)] RAA (probably justified now given the d+Au results). Let's see at higher pT.
• s dependence of Au+Au suppression clear ?
  • No jet quenching observed in Pb+Pb @ SPS with dNg/dy ~ 500 ?
  • Usual explanations: short plasma t, quark-dominated plasma, very small hard cross-sections (Cronin-effect dominates) ...
  • (Perhaps just a problem in the p+p reference @ √s ≈ 17 GeV ?)
• Particle species dependence of Au+Au suppression (“baryon enhancement”)  not perturbative !
  • Additional final state effects needed: q recombination (or baryon junctions, ... ?).

Notes: