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Larissa Bravina (UiO) pp, flow, freeze-out, HBT, charm-beauty, HYDJET++, Shadowing, small x physics I. Arsene , K.Tywoniuk , Dr. E. Zabrodin Flow in pp Dr. R. Kolevatov , HBT, flow, jets (ALICE and BRAHMS) : I. Arsene , Dr. L. Malinina , PhD G. Eyyubova , PhD M.S.Nilsson.
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LarissaBravina (UiO) pp, flow, freeze-out, HBT, charm-beauty, HYDJET++, Shadowing, small x physics I. Arsene, K.Tywoniuk, Dr. E. Zabrodin Flow in pp Dr. R. Kolevatov, HBT, flow, jets (ALICE and BRAHMS) : I. Arsene, Dr. L. Malinina, PhD G. Eyyubova, PhD M.S.Nilsson Bergen town-meeting, 13.04.2010 TheoryContribution to studyofrelativistic Heavy ion collisions at LHC
1. Gluon shadowing 6. Equation of State Oslo Heavy-iontheorygroup(projects) 4. Freeze-out 2. Elliptic flow 7. Predictions for pp 5. HBT correlations 3. HYDJET++ 8. Flow in pp 9. Di-hadron azimuthal correl. …
1.Shadowing:Comparisonwith RHIC Au+au @ 200 Gev A. Capella, L.B., E. Ferreiro, A. Kaidalov, K. Tywoniuk, E. Zabrodin, Eur. Phys. J C58 (2008) 437 • weaker comover suppression at forward • weaker recombination at forward • stronger initial state effects! no adjusted parameters!
1. shadowing: predictions for LHC K. Tywoniuk, L.B. et al., J. Phys. G 35 (2008) 104156 A. Capella, L.B. et al., Eur. Phys. J. C 58 (2008) 437
2. HYDJET++ = HYDJET + FASTMC I. Lokhtin et al., Comput. Phys. Commun. 180 (2009) 779 N. Amelin, … L.B. … et al., Phys. Rev. C 77 (2008) 014903 FASTMC HYDJET HYDJET++ K. Tywoniuk, L.B. et al., Phys. Lett. B 657 (2007) 170
3. Elliptic flow in HYDJET++ Hydro flow Jet contribution The model possesses crossing of baryon and meson branches. Hydrodynamics gives mass ordering of v2 G. Eyyubova, L.B. et al., Phys. Rev. C80 (2009) 064907; arxiv:1001.3602[hep-ph]
3. ELLIPTIC FLOW: predictions for LHC L. B., G. Eyyubova et al., arXiv:1001.3602; PRC 80 (2009) 064907 20% RHIC Hydro+jets = reduction of flow LHC 44% Influence of resonance decays
Constituent Quark Scaling at LHC No scaling for Appearance of the approximate direct particles scaling for all particles LHC: NCQ scaling will be only approximate SQM’09, Buzios, Brasil, 27.09-02.10.2009
4. Freeze-out at RHIC: UrQMD M.S. Nilsson, ”LHC and beyond” (Lund, Feb. 2009)
freeze-out at RHIC: QGSM M.S. Nilsson , ”LHC and beyond” (Lund, Feb. 2009)
5. Hanbury-Brown—Twisscorrelations M.S. Nilsson , L.B. et al. (to be submitted) Detector Detector
Non-Identical HBT correlations M.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)
Identical HBT correlations M.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)
6. EQUILIBRATION IN THE CENTRAL CELL (FAIR) Kinetic equilibrium: Isotropy of velocity distributions Isotropy of pressure Thermal equilibrium: Energy spectra of particles are described by Boltzmann distribution Chemical equlibrium:Particle yields are reproduced by SM with the same values of
EOS: HOW DENSE CAN BE THE MEDIUM? L. B. et al., Phys. Rev. C 78 (2008) 014907 ”Big” cell (V = 5x5x5 fm^3) “Small” cell (V => 0) Dramatic differences at the non-equilibrium stage; after beginning of kinetic equilibrium the energy densities and the baryon densities are the same for ”small” and ”big” cell
EOS IN THE CELL: OBSERVATION OF KNEE temperature vs. chemical potentials L.B. et al., PRC 78 (2008) 014907; E. Zabrodin, L.B. et al, arXiv:0902.4601 S. Ejiri et al., PRD 73 (2006) 054506 Although the “knee” is similar to that in 2-flavor lattice QCD, it is related to inelastic (chemical) freeze-out in the system
A.B. Kaidalov, K.A.Ter-Martirosyan, PLB 117 (1982) N.S.Amelin, L.B., Sov.J.Nucl.Phys. 51 (1990) 133 N.S.Amelin, E.F.Staubo, L.P.Csernai, PRD 46 (1992) 4873 7. QGSM PREDICTIONS FOR PP AT LHC At ultra-relativistic energies: multi-Pomeron scattering, single and double diffraction, and jets (hard Pomeron exchange) Gribov’s Reggeon Calculus + string phenomenology
PREDICTIONS FOR LHC Inelastic collisions NSD collisions
PREDICTIONS FOR PP @ LHC QGSM: extended longitudinal scaling in p+p collisions holds
VIOLATION OF KNO SCALING AT LHC High-multiplicity tail is pushed up, whereas maximum of the distribution is shifted towards small values of z At energies below 100 GeV different contributions overlap strongly, whereas at higher energies – more multi-string processes 2 4 6 8 => Enhancement of high multiplicities
Summary and outlook • LHC is a discovery machine for both hard and soft physics in HI collisions • Event generators are an indispensable tool for planing the experiments and analysis of data • => Further development of existing MC generators • HI theory groups in Oslo utilizes it to study : EOS, elliptic flow, particle freeze-out, HBT correlations of unlike particles, particle-jet correlations, heavy quark production in a large pT range, scaling properties …
Motivation: ExperimentalResults W. Busza, JPG 35 (2008) 044040 e+e- Example of extended longitudinal scaling in different reactions
violationofFeynmanscaling UA5 Collab., Phys. Rep. 154 (1987) 247 W. Busza, JPG 35 (2008) 044040 Violation of Feynman scaling, but ext. long. scaling holds?! Charged particle pseudorapidity density at h = 0 as a function of √s
VIOLATION OF ELS IN A+A AT LHC? J. Cleymans, J.Struempfer, L.Turko, PRC 78 (2008) 017901 s Statistical thermal model: ELS will be violated in A+A @ LHC. What about p+p ?
WHY SCALING HOLDS IN THE MODEL? Short range correlations In string models both FS and ELS holds in the fragmentation regions
VIOLATION OF KNO SCALING A.B.Kaidalov, K.A.Ter-Martirosyan, PLB 117 (1982) 247 UA5 Collaboration, Phys. Rep. 154 (1987) 247 N.S.Amelin, L.V.Bravina, Sov.J.Nucl.Phys. 51 (1990) 133 Charged-particle multiplicity distributions in the KNO variables in nondiffractive antiproton-proton collisions at √s = 546 GeV and 53 GeV √s