1 / 39

The importance of multiparticle collisions in heavy ion reactions

This study explores the significance of multiparticle collisions in heavy ion reactions, with a focus on the equilibration of anti-baryons and baryons. It discusses the thermalization processes and the production of anti-baryons in the Quark-Gluon Plasma (QGP) phase.

seibold
Download Presentation

The importance of multiparticle collisions in heavy ion reactions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Johann Wolfgang Goethe-Universität Frankfurt Institut für Theoretische Physik The importance of multiparticle collisions in heavy ion reactions C. Greiner The Physics of High Baryon Density IPHC Strasbourg, Sept. 2006 • Motivation: chemical equilibration of anti-baryons • Equilibration by potential Hagedorn states • Thermalization at RHIC by • Outlook

  2. Exploring the phases of nuclear matter

  3. Strangeness production at SpS energies Production of Antihyperons: QGP signature…? J. Geiss P. Koch, B. Müller, J. Rafelski

  4. Production of Anti-Baryons Multimesonic channels R.Rapp and E. Shuryak, Phys.Rev.Lett.86(2001) 2980 C.Greiner and S.Leupold, J.Phys. G27(2001) L95

  5. C.Greiner, AIP Conf. Proc. 644:337 (2003)

  6. production at RHIC Thermal rates within chiral SU(3) description Chemical population of baryons / anti-baryons: I. Shovkovy, J. Kapusta P. Huovinen, J. Kapusta Insufficient by a factor of 3 to 4

  7. Chemical Freeze-out and of QCD (P. Braun-Munzinger, J. Stachel, C. Wetterich,Phys.Lett.B596:61-69 (2004)) Chemical equilibration of baryon / anti-baryons: Hadronic resonance gas vs. lattice: Multimesonic channels:

  8. Possible solution by Hagedorn states C. Greiner, P. Koch, F. Liu, I. Shovkovy, H. Stöcker J.Phys.G31 (2005)

  9. K. Redlich et al, K. Bugaev et al Hagedorn gas close to • Hagedorn spectrum: • Hagedorn like excitations • in transport models: RQMD HSD

  10. Estimate for baryon/antibaryon production

  11. Microcanonical decay of HS (Fuming Liu)

  12. Master Equations for the decay HS→nπ+BaB dNR(i)/dt=-GiNR(i)+ånGi,p<i,n(T) (Np)nBi!np+Gi,BaB<i,<n>BaB (T)(Np)<n> N2BaB dNp/dt=åiånGi,pnBi! np(NR(i)-< (T) (Np)n)+åiGi,BaB<n>(NR(i)-<i,<n>BaB(T)(Np)<n>N2BaB) dNBaB/dt=-åiGi,BaB(NBaB2 Np<n><i,<n>(T)-NR(i)) J. Noronha-Hostler TexPoint fonts used in EMF: AAAAAAA

  13. Considering the decayHS→nπ

  14. HS→nπ+BaB Nπ(t=0)=Equilibrium NRes(t=0)=0 Nπ (t=0)=Equilibrium NRes(t=0)=Equilibrium

  15. HS→nπ+BaBwhen the Hagedorn Resonances start at twice equilibrium values and the rest starts at zero.

  16. HS→nπ+BaBwhen the Hagedorn Resonances start at twice equilibrium values and the rest starts at equilibrium.

  17. The strange sector of baryons/antibaryons

  18. Importance of baryonicHS CBM?

  19. The order and shape of QGP phase transition nucl-th/0605052, I. Zakout, CG and J. Schaffner-Bielich density of states:

  20. Thermalization at RHIC elliptic flow --- `early signature´ of QGP evidence for an early buildup of pressure and a fast thermalization of the quark-gluon system • How can one describe the fast thermalization by the partonic collisions? • How can one understand the hydrodynamical behavior by the partonic collisions? transport simulation: on-shell parton cascade Z. Xu and C. Greiner, PRC 71, 064901 (2005) solving the Boltzmann-equations for quarks and gluons new development (Z)MPC, VNI/BMS

  21. Initial production of partons minijets string matter

  22. Stochastic algorithm P.Danielewicz, G.F.Bertsch, Nucl. Phys. A 533, 712(1991) A.Lang et al., J. Comp. Phys. 106, 391(1993) cell configuration in space D3x for particles in D3x with momentum p1,p2,p3 ... collision probability: parton scatterings in leading order pQCD

  23. the central region: h: [-0.5:0.5] and xt < 1.5 fm including gg<->ggg without gg<->ggg thermalization and hydrodynamical behavior NO thermalizationand free streaming

  24. transverse energy at y=0 in Au+Au central collision

  25. elliptic flow in noncentral Au+Au collisions at RHIC: peripheral central

  26. Comparison with RHIC data

  27. Conclusions and Outlook • Potential Hagedorn states as additional dof can explain and also strangebaryon production close to ; (re-)population and decay are governed by detailed balance • Three main assumptions: (1): (2): (3): microcanonical statistical decay • Multiparticle interactions also important for very high energies ( ) • Future: Embedding into UrQMD

  28. free ρ in-medium Nonequilibrium dilepton production (B. Schenke) Spectral function of the ρ-meson: CERES → quantum “off-shell”-transport description

  29. Non-equilibrium dilepton production rate: Contributions to therate at time τat constant energy ω Evolving spectral function and dilepton rate B. Schenke, C. Greiner, Phys.Rev.C73:034909 (2006)

  30. (B. Schenke) Dilepton yields from fireball Dropping mass (linearly in time) and resonance coupling scenarios for k=0: Dropping mass scenario integrated over momenta: B. Schenke, C. Greiner, Phys.Rev.C73:034909 (2006) B. Schenke, C. Greiner, arXiv:hep-ph/0608032 (2006)

More Related