Pinning down QCD-matter shear viscosity in A+A collisions via EbyE fluctuations using pQCD + saturation + hydrodynamics

Abstract

We compute the initial energy densities produced in ultrarelativistic heavy-ion collisions from NLO perturbative QCD using a saturation conjecture to control soft particle production, and describe the subsequent space-time evolution of the system with hydrodynamics, event by event. The resulting centrality dependence of the low-$p_T$ observables from this pQCD + saturation + hydro ("EKRT") framework are then compared simultaneously to the LHC and RHIC measurements. With such an analysis we can test the initial state calculation, and constrain the temperature dependence of the shear viscosity-to-entropy ratio $\eta /s$ of QCD matter. Using these constraints from the current RHIC and LHC measurements we then predict the charged hadron multiplicities and flow coefficients for the 5.023 TeV Pb+Pb collisions.

4 pages, Quark Matter 2015 proceedings

References in corpus (4)

• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• Predictions for 5.023 TeV Pb+Pb collisions at the LHC
• Multiplicities and $p_T$ spectra in ultrarelativistic heavy ion collisions from a next-to-leading order improved perturbative QCD + saturation + hydrodynamics model
• Minijet initial state of heavy-ion collisions from next-to-leading order perturbative QCD

Cited by in corpus (3)

• Quasiparticle anisotropic hydrodynamics for central collisions
• Quark self-energy in an ellipsoidally anisotropic quark-gluon plasma
• Overview of ALICE results in pp, pA and AA collisions