Non-thermal p/pi ratio at LHC as a consequence of hadronic final state interactions

Abstract

Recent LHC data on Pb+Pb reactions at sqrt(s_{NN})=2.7 TeV suggests that the p/pi is incompatible with thermal models. We explore several hadron ratios (K/pi, p/pi, Lambda/pi, Xi/pi) within a hydrodynamic model with hadronic after burner, namely UrQMD 3.3, and show that the deviations can be understood as a final state effect. We propose the p/pi as an observable sensitive on whether final state interactions take place or not. The measured values of the hadron ratios do then allow to gauge the transition energy density from hydrodynamics to the Boltzmann description. We find that the data can be explained with transition energy densities of 840 +- 150 MeV/fm^3.

4 pages, 2 figures, version accepted by PRL

References in corpus (6)

• Fully integrated transport approach to heavy ion reactions with an intermediate hydrodynamic stage
• Space-time evolution of bulk QCD matter
• Anisotropic flow in sqrt(s)=2.76 TeV Pb+Pb collisions at the LHC
• Mass ordering of differential elliptic flow and its violation for phi mesons
• Elliptic flow in Pb+Pb collisions at sqrt{s_{NN}} = 2.76 TeV: hybrid model assessment of the first data
• Statistical hadronization of charm: from FAIR to the LHC

Cited by in corpus (18)

• Freeze-out parameters from electric charge and baryon number fluctuations: is there consistency?
• The ALICE experiment: a journey through QCD
• Centrality dependence of hadronization and chemical freeze-out conditions in heavy ion collisions at \sqrt s_{NN} = 2.76 TeV
• The QCD phase diagram and Beam Energy Scan physics: a theory overview
• An overview of experimental results from ultra-relativistic heavy-ion collisions at the CERN LHC: bulk properties and dynamical evolution
• Production of Light Nuclei in Heavy Ion Collisions Within Multiple Freezeout Scenario
• Understanding the $p/\pi$ ratio at LHC due to QCD mass spectrum
• Evolving Charge Correlations in a Hybrid Model with both Hydrodynamics and Hadronic Boltzmann Descriptions
• Solving the puzzle of high temperature light (anti)-nuclei production in ultra-relativistic heavy ion collisions
• Energy dependence of light hypernuclei production in heavy-ion collisions from a coalescence and statistical-thermal model perspective
• Magnetic field effect on hadron yield ratios and fluctuations in a hadron resonance gas
• Centrality dependence of proton and light nuclei yields as a consequence of baryon annihilation in the hadronic phase
• Using Baryonic Charge Balance Functions to Resolve Questions about the Baryo-Chemistry of the QGP
• Quark flavor equilibration of the quark-gluon plasma
• Viewing the Chemical Evolution of the Quark-Gluon Plasma with Charge Balance Functions
• Studies of final state interactions via femtoscopy in ALICE
• Quantifying the Quark Gluon Plasma
• Extracting the strangeness freeze-out temperature from net-Kaon data at RHIC