9 th June 2008 Seminar at UC Riverside Probing the QCD Phase Diagram Aneta Iordanova 2 9 th June 2008 Aneta Iordanova University of Illinois at Chicago UC Riverside Outline Motivation Analysis Technique Freeze-out Chemical Kinetic Baryon/meson and strangeness production Scaling properties 3 9 th June 2008 Aneta Iordanova University of Illinois at Chicago UC Riverside Motivation Identified particle spectra in heavy-ion collisions at different center-of-mass energies and system size provide: a unique tool to explore the QCD phase diagram. system size dependence of the freeze-out parameters at RHIC. Bulk particle production provide: Kinetic freeze-out properties from spectral shapes T kin at kinetic freeze-out, transverse radial flow () Chemical freeze-out properties from particle ratios T ch at chemical freeze-out, strangeness and baryon production 4 9 th June 2008 Aneta Iordanova University of Illinois at Chicago UC Riverside Heavy ion collision evolution Experimental Observation: the bulk of produced matter is soft (99%) to study the QGP study hadronization and properties of produced particles species abundances (Chemical freeze-out and equilibration) momentum distributions (Kinetic freeze-out) Collision Hard Partonic Scattering Hot, Dense Matter, QGP? Hadronization Phase Inelastic Scattering Elastic Scattering the current view Chemical Freeze-out Kinetic Freeze-out q q time: the system cools and expands 5 9 th June 2008 Aneta Iordanova University of Illinois at Chicago UC Riverside Mapping the QCD Phase Diagram Lattice QCD predicts critical temperature for QGP phase boundary: T c ~ 170 MeV c ~ 1 GeV/fm 3 Experimentally derived freeze- out parameters from different experiments Extend the measurements at RHIC over a broad range of Energy Centrality System size J.Stachel (Trento 2004) 6 9 th June 2008 Aneta Iordanova University of Illinois at Chicago UC Riverside STAR Experiment Time Projection Chamber Measures charged particle momenta and energy loss within | |