Phases of QCD, Thermal Quasiparticles and Dilepton Radiation from a Fireball

Abstract

We calculate dilepton production rates from a fireball adapted to the kinematical conditions realized in ultrarelativistic heavy ion collisions over a broad range of beam energies. The freeze-out state of the fireball is fixed by hadronic observables. We use this information combined with the initial geometry of the collision region to follow the space-time evolution of the fireball. Assuming entropy conservation, its bulk thermodynamic properties can then be uniquely obtained once the equation of state (EoS) is specified. The high-temperature (QGP) phase is modelled by a non-perturbative quasiparticle model that incorporates a phenomenological confinement description, adapted to lattice QCD results. For the hadronic phase, we interpolate the EoS into the region where a resonance gas approach seems applicable, keeping track of a possible overpopulation of the pion phase space. In this way, the fireball evolution is specified without reference to dilepton data, thus eliminating it as an adjustable parameter in the rate calculations. Dilepton emission in the QGP phase is then calculated within the quasiparticle model. In the hadronic phase, both temperature and finite baryon density effects on the photon spectral function are incorporated. Existing dilepton data from CERES at 158 and 40 AGeV Pb-Au collisions are well described, and a prediction for the PHENIX setup at RHIC for sqrt(s) = 200 AGeV is given.

31 pages, 15 figures, final version

References in corpus (10)

• Hadron production in Au-Au collisions at RHIC
• Lattice Results on QCD Thermodynamics
• On the Quasiparticle Description of Lattice QCD Thermodynamics
• Temporal quark and gluon propagators: measuring the quasiparticle masses
• Ratios of charged antiparticles to particles near mid-rapidity in Au+Au collisions at sqrt(s_NN) = 130 GeV
• Constraints on quark energy loss from Drell-Yan data
• Temperature dependence of rho- and a_1-meson masses and mixing of vector and axial-vector correlators
• Overview of PHENIX Results from the First RHIC Run
• The omega meson at high temperatures
• HBT and Fluctuations: Recent Results

Cited by in corpus (35)

• First observation of in-medium modifications of the omega meson
• e+e--pair production in Pb-Au collisions at 158 GeV per nucleon
• Dilepton production and off-shell transport dynamics at SIS energies
• The Chiral Restoration Transition of QCD and Low Mass Dileptons
• Anisotropy of flow and the order of phase transition in relativistic heavy ion collisions
• Low Mass Dimuons Produced in Relativistic Nuclear Collisions
• Light Vector Mesons in the Nuclear Medium
• Lattice QCD Constraints on the Nuclear Equation of State
• Dimuon transverse momentum spectra as a tool to characterize the emission region in heavy-ion collisions
• Polyakov Loops versus Hadronic States
• Equation of state of deconfined matter within dynamical quasiparticle description
• Glueball Dark Matter revisited
• QCD sum rules for rho mesons in vacuum and in-medium, re-examined
• Lattice QCD Constraints on Hybrid and Quark Stars
• A Simple Statistical Model for Analysis of QGP-droplet (Fireball) Formation
• Emission of thermal photons and the equilibration time in Heavy-Ion collisions
• Kinetic description of charmonium production in high-energy nuclear collisions
• Meson correlation functions in a QCD plasma
• Non-perturbative finite $T$ broadening of the $\rho$ meson and dilepton emission in heavy ion-collisions
• A comprehensive description of multiple observables in heavy-ion collisions at SPS
• Partial Deconfinement in Color Superconductivity
• Why a long-lived fireball can be compatible with HBT measurements
• Glueball dark matter, precisely
• In-medium Properties of Hadrons -- Observables
• Effective distributions of quasi-particles for thermal photons
• Dilepton emission rates from hot hadronic matter
• In-Medium Properties of Hadrons - Observables II
• Collective Phenomena in the Non-Equilibrium Quark-Gluon Plasma
• Statistical Hadronization as a Snapshot of a dynamical Fireball Evolution
• What does the rho-meson do? In-medium mass shift scenarios versus hadronic model calculations
• Low energy ω(\to π^0 γ) meson photoproduction in the nucleus
• Broadening of $\rho (\to e^{+}{e}^{-})$ meson produced coherently in the photonuclear reaction
• Omega mesons in medium - revisited
• A global description of heavy-ion collisions
• Hadrons in Nuclei