6533b82cfe1ef96bd128f6fd

RESEARCH PRODUCT

A first estimate of $\eta/s$ in Au+Au reactions at E$_{\rm lab}=1.23$ $A$GeV

Marcus BleicherG. InghiramiG. InghiramiTom Reichert

subject

Nuclear and High Energy PhysicsNuclear TheoryQC1-999relativistic [quantum molecular dynamics]hiukkasfysiikka7. Clean energy01 natural sciencesNuclear physicsscattering [heavy ion]low [energy]0103 physical sciencestransport theoryddc:530numerical calculations010306 general physicsNuclear ExperimentNuclear theoryNuclear Experiment1.23 GeV/nucleonPhysicsdensity010308 nuclear & particles physicsPhysicsShear viscosityrelativistic heavy ion collisionsEntropy densityHADESflowHarmonicsviscosityHigh Energy Physics::ExperimentGranularityentropy

description

The HADES experiment at GSI has recently provided data on the flow coefficients $v_1,...,v_4$ for protons in Au+Au reactions at $E_{\rm lab} = 1.23$~$A$GeV (or $\sqrt{s_\mathrm{NN}}=2.4$ GeV). This data allows to estimate the shear viscosity over entropy ratio, $\eta/s$ at low energies via a coarse graining analysis of the UrQMD transport simulations of the flow harmonics in comparison to the experimental data. By this we can provide for the first time an estimate of $\eta/s\approx0.65\pm0.15$ (or $(8\pm2)\,(4\pi)^{-1}$) at such low energies.

yearjournalcountryeditionlanguage
2020-11-09
10.1016/j.physletb.2021.136285http://arxiv.org/abs/2011.04546