Entropy production in pp and Pb-Pb collisions at energies available at the CERN Large Hadron Collider

Abstract

We use experimentally measured identified particle spectra and Hanbury Brown-Twiss radii to determine the entropy per unit rapidity $dS/dy$ produced in $\sqrt{s}=7$ TeV pp and $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV Pb-Pb collisions. We find that $dS/dy=11335\pm 1188$ in 0-10% Pb-Pb, $dS/dy=135.7\pm 17.9$ in high-multiplicity pp, and $dS/dy=37.8\pm 3.7$ in minimum bias pp collisions and compare the corresponding entropy per charged particle $(dS/dy)/(d{N}_{\mathrm{ch}}/dy)$ to predictions of statistical models. Finally, we use the QCD kinetic theory pre-equilibrium and viscous hydrodynamics to model entropy production in the collision and reconstruct the average temperature profile at ${\tau }_0=1$ fm/$c$ for high multiplicity pp and Pb-Pb collisions.

13 pages, 9 figures; added an appendix on relation between 1D and 3D HBT radii, updated references, small corrections, published version

References in corpus (12)

• PYTHIA 6.4 Physics and Manual
• Glauber Modeling in High Energy Nuclear Collisions
• The equation of state in (2+1)-flavor QCD
• Alternative ansatz to wounded nucleon and binary collision scaling in high-energy nuclear collisions
• Phobos results on charged particle multiplicity and pseudorapidity distributions in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies
• Entropy production in collisions of gravitational shock waves and of heavy ions
• Therminator: Thermal heavy-Ion generator
• Thermal-FIST: A package for heavy-ion collisions and hadronic equation of state
• Measurement of the pseudorapidity and centrality dependence of the transverse energy density in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
• SHAREv2: fluctuations and a comprehensive treatment of decay feed-down
• Pion, kaon, and proton femtoscopy in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$=2.76 TeV modeled in 3+1D hydrodynamics
• Hydrodynamic flow in small systems, or: "How the heck is it possible that a system emitting only a dozen particles can be described by fluid dynamics?"

Cited by in corpus (19)

• QCD thermalization: Ab initio approaches and interdisciplinary connections
• Thermodynamics of hot strong-interaction matter from ultrarelativistic nuclear collisions
• Hydrodynamic attractors, initial state energy and particle production in relativistic nuclear collisions
• The mean transverse momentum of ultracentral heavy-ion collisions: A new probe of hydrodynamics
• Equilibration of the Quark-Gluon Plasma at finite net-baryon density in QCD kinetic theory
• Intermediate mass dileptons as pre-equilibrium probes in heavy ion collisions
• Effective shear and bulk viscosities for anisotropic flow
• Investigating the QCD dynamical entropy in high-energy hadronic collisions
• Accessing the speed of sound in relativistic ultracentral nucleus-nucleus collisions using the mean transverse momentum
• Minijet quenching in non-equilibrium quark-gluon plasma
• Fluid velocity from transverse momentum spectra
• Hanbury Brown--Twiss Interferometry and Collectivity in Small Systems
• Entropy per rapidity in Pb-Pb central collisions using Thermal and Artificial neural network(ANN) models at LHC energies
• Multiplicity fluctuations and correlations in 5.02 TeV p+Pb collisions at zero impact parameter
• Collective flow in single-hit QCD kinetic theory
• The size of the quark-gluon plasma in ultracentral collisions: impact of initial density fluctuations on the average transverse momentum
• Hard gluon evolution in warming medium
• Extracting the speed of sound of QCD from transverse momentum fluctuations
• Applicability of Hydrodynamics in Hadronic Phase of Heavy-Ion Collisions