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Larissa Bravina, UiO, NFR meeting 10.11.2004, Oslo

LHC Physics: theory perspectives. Larissa Bravina, UiO, NFR meeting 10.11.2004, Oslo. Larissa Bravina UiO Microscopic models Eivind Osnes UiO Phase transition dynamics Laszlo P. Csernai UiB Hydrodynamics Eugene Zabrodin _ Microscopic Models

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Larissa Bravina, UiO, NFR meeting 10.11.2004, Oslo

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  1. LHC Physics: theory perspectives Larissa Bravina, UiO, NFR meeting 10.11.2004, Oslo • Larissa Bravina UiO Microscopic models • Eivind Osnes UiO Phase transition dynamics • Laszlo P. Csernai UiB Hydrodynamics • Eugene Zabrodin _ Microscopic Models • Konrad Tywoniuk UiOAgnes Nyiri ** NFRKarolis Tamosiunas Etele MolnarJaakkoo Manninen Moscow State University, ITEP, Dubna, Serpukhov, Los Alamos National Laboratory, Univ. of Valencia, University of Minnesota, University of Franfurt, University of Tuebingen, University of Pensilvania, University of Tel Aviv

  2. LHC Physics: theory perspectives Larissa Bravina, UiO, NFR meeting 10.11.2004, Oslo • QCD, asymptotic freedom and quark – hadron phase transition • Super-colliders – tools to study Big Bang in the laboratory? • Lattice QCD – another tool to study partonic mater at extreme conditions • Semi-phenomenological models for heavy ion collisions • Modern interpretation of the experimental data • LHC perspectives

  3. Pb+Pb at LHC: Quantitatively new regime Y. Schutz QM 2004

  4. 100 GeV 10 GeV 10-6 10-4 10-2 100 x J/y Qualitatively new regime Heavy Ions at the LHC: • Probe initial partonic state in a novel Bjorken-x range (10-2-10-5): • nuclear shadowing, • high-density saturated gluon distribution. • Larger saturation scale (QS=0.2A1/6√sg= 2.7 GeV): particle production dominated by the staturation region. M2 (GeV2) ALICE PPR CERN/LHCC 2003-049

  5. initial LHC state RHIC LHC Quark Gluon Plasma – consequence of asymptotic freedom QCD phase diagram :

  6. UrQMD-Phase diagram UrQMD: L.V. Bravina et al PRC 62 (2000) 064906, 63(2001) 064902 • QGP might be reachedalready at low SPS energy ! • Tricritical point around 10-40 GeV • No 1st order phase transition at RHIC • Necessary to explore 10-30 AGeV energy region to study the phase transition

  7. QGP = quark-gluon plasma sQGP? ? Hadron gas Lattice QCD – first principle theory But : Lattice QCD cannot be directly applied for description of heavy ion collisions QCD equation of state from lattice QCD

  8. Applicability of different models

  9. Statistical thermal model

  10. Initial condition L.P. Csernai, Summary talk at SQM 2004, Cape Town • Alternative (more demanding) approach: all (or part) of parameters are calculated from the principal collisionparameters in an INITIAL STATE MODEL: • Nexus in NexSpherio • Parton Cascade • Yang Mills FT model – Color Glas Condensate • Yang Mills FT model - Color Flux tube streaks 3rd Flow Component (Anti-flow) [Grassi–SQM2004] [Magas, Csernai, Strottman, Phys. Rev. C64 (01) 014901] L.P. Csernai, D. Roehrich , PLB 458 (1999) 454

  11. L.P. Csernai UiB, et al Hydrodynamics Bjorken-Formula for Energy Density: PRD 27, 140 (1983) – watch out for typo (factor 2) Time it takes to thermalize system (t0 ~ 1 fm/c) ~6.5 fm pR2 Central Au+Au (Pb+Pb) Collisions: 17 GeV: eBJ  3.2 GeV/fm3 130 GeV: eBJ 4.6 GeV/fm3 200 GeV: eBJ  5.0 GeV/fm3 Note: t0 (RHIC) < t0 (SPS) commonly use 1 fm/c in both cases

  12. Single Gaussians all the rage 2004 Au+Au 200AGeV L.D. Landau, Izv. Akad. Nauk SSSR 17 (1953) 52 Pb+Pb 17.2 AGeV 12.3 AGeV 8.8 AGeV 7.6 AGeV 6.3 AGeV NA49 double-gaussians  single-gaussians.BRAHMS always fit a single gaussian. Width systematics predicted in 1953 by Landau

  13. Microscopic Modelsfor relativistic heavy ion collisions UrQMD animation forAu+Au collisions at 200 AGeV (RHIC BNL energy) and Pb+Pb at 5500 GeV (LHC CERN)

  14. 1 3 2 Outline soft physics regime hard (high-pT) probes Chemical freezeout (Tch  Tc): inelastic scattering ceases Kinetic freeze-out (Tfo Tch): elastic scattering ceases

  15. LHC Predictions for Pb+Pb at 5500 GeV Different Monte Carlo model predictions: Alice technical proposal CERN/LHCC 95-71 VenusShakerHIJINGDPMJETSFM w/o SFSFM with SF Monte Carlo Models should be fixed!!!!

  16. RHIC LHC From RHIC to LHC (I) Eskola, Honkanen, Salgado & Wiedemann, hep-ph/0406319

  17. From RHIC to LHC (II) I. Vitev, M. Gyulassy, PRL 89 (2002) 252301

  18. Summary and outlook: • Experiments:BRAHMS, PHENIX, PHOBOS, STAR (pp, dAu Au+Au collisions at 19.4, 62, 130 and 200 GeV) : “There is compelling experimental evidence that the matter created at RHIC differs from anything that has been seen before. Still there is no direct indication of QGP formation” • Accelerator facilities will be upgraded by order of magnitude (LHC in 2007) • Super processors for Lattice QCD will be upgraded at least order of magnitude (2004-2005) • Microscopic and hydrodynamic models need urgently manpower for describing physics at LHC

  19. From the summary talk at LHC Physics 2004 by Chris Quigg

  20. SPS: First glimpse (“evidence”) of the QGP • RHIC: Discovery of the (s)QGP ?! • LHC: Exploration and quantitative confirmation of the QGP facilitated by plentiful hard probes, which are accessible to theoretical treatment ! • Specific questions: • How does dE/dx depend on energy density? • How is the fragmentation function modified? • Are c (and b) quarks thermalized? • Gluon saturation in nuclei at small x

  21. The cartoon shown by Weisskopf at the conclusion of the 1962 ICHEP in Geneva is still timely

  22. TungionefysikkProsjekt i grenseland mellom partikkel- og kjernefysikk “Hva skjer når to tunge atomkjerner kolliderermed 99.995% av lysets hastighet?” Eksperimenter Teori P: G. Løvhøiden, T. Tveter, L. Bravina, E. Zabrodin D: B. Samset, T. Vik, H: S. Lindal K. Tywoniuk

  23. Heavy Ion Theory:Monte Carlo simulations of heavy ion collisions Larissa Bravina, Eugeni Zabrodin, Konrad Tywoniuk Topics for master students: Global properties of p+p, d+Au and Au+Au collisions at RHIC and LHC Collective effects Hard probes and jet quenching HBT correlations Freeze-out EOS of the strongly interacting matter http://www.fys.uio.no/~bjornhs/theory_project/

  24. Thermalization and Freeze-Out What can final-state particle yields and momenta tell us about thermal conditions at freeze-out? Chemical freeze-out (yields & ratios) • inelastic interactions cease • particle abundances fixed (except maybe resonances) Thermal freeze-out (shapes of pT,mT spectra): • elastic interactions cease • particle dynamics fixed

  25. Statistical Models in RHI Collisions • Where in the phase diagram is the system at chemical freeze-out? • What values have Tch, B ? • Statistical Thermal Models: a means to extract (Tch, B) from particle ratios

  26. 1 3 2 Outline soft physics regime hard (high-pT) probes Chemical freezeout (Tch  Tc): inelastic scattering ceases Kinetic freeze-out (Tfo Tch): elastic scattering ceases

  27. Almond shape overlap region in coordinate space Collective effects in Heavy Ion Collisions Origin: spatial anisotropy of the system when created, followed by multiple scattering of particles in the evolving system spatial anisotropy  momentum anisotropy v2: 2nd harmonic Fourier coefficient in azimuthal distribution of particles with respect to the reaction plane

  28. Hard probes and jet quenching Bjorken, Baier, Dokshitzer, Mueller, Pegne, Schiff, Gyulassy, Levai, Vitev, Zhakarov, Wang, Wang, Salgado, Wiedemann,… Multiple soft interactions: Gluon bremsstrahlung Strong dependence of energy loss on gluon density glue: measure DEcolor charge density at early hot, dense phase

  29. schematic view of jet production hadrons leading particle q q hadrons leading particle q/g jets as probe of hot medium Jets from hard scattered quarks observed via fast leading particles or azimuthal correlations between the leading particles • However, before they create jets, the scattered quarks radiate energy (~ GeV/fm) in the colored medium • decreases their momentum (fewer high pT particles) • “kills” jet partner on other side Jet Quenching

  30. Connection to QCD Initial State ‘Final State’ Interactions Interaction of fast partons with dense medium has been observed Quantitative diagnostic tool now established Multiplicity systematics connected to initial state Consistent with parton saturation picture

  31. Hydrodynamics: Modeling High-Density Scenarios • Assumes local thermal equilibrium (zero mean-free-path limit) and solves equations of motion for fluid elements (not particles) • Equations given by continuity, conservation laws, and Equation of State (EOS) • EOS relates quantities like pressure, temperature, chemical potential, volume • direct access to underlying physics Kolb, Sollfrank & Heinz, hep-ph/0006129 lattice QCD input

  32. "Physics will change even more. If it is radical and unfamiliar and a lesson that we are not likely to forget, we think that the future will be only more radical and not less, only more strange and not more familiar, and that it will have its own new insights for the inquiring human spirit." J. R. Oppenheimer

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