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Strange particles and neutron stars - experiments at GSI. Peter Senger (GSI). Outline: Probing dense baryonic matter (1-3 ρ 0 ) The nuclear equation-of-state In medium properties of strange mesons Towards highest baryon densities (3-10 ρ 0 ) Exploring the phases of QCD matter.
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Strange particles and neutron stars - experiments at GSI Peter Senger (GSI) Outline: Probing dense baryonic matter (1-3 ρ0) The nuclear equation-of-state In medium properties of strange mesons Towards highest baryon densities (3-10 ρ0) Exploring the phases of QCD matter International Symposium on Heavy-Ion Physics, April 2-6, 2006, Frankfurt
Strongly interacting matter in neutron stars color superconductor ? “Strangeness" of dense matter ? In-medium properties of hadrons ? Nuclear matter equation of state ? Deconfinement at high baryon densities ? nucleon star: kaon condensate F. Weber J.Phys. G27 (2001) 465
Kaon production in Au+Au collisions at 1 AGeV u d d u d s u d s u d u L p n d u s u u u s u K- K+ p+ p0 K+ mesons probe high densities K-absorption
Probing the nuclear equation-of-state at high density by K+ meson production in C+C and Au+Au collisions C. Sturm et al., Phys. Rev. Lett. 86 (2001) 39 Idea: K+ yield baryon density ρ compressibility κ Au+Au at 1 AGeV (RBUU): soft eos ρmax 2.9 ρ0 K+ yield up hard eos ρmax 2.4 ρ0 K+ yield down but: in C+C no influence of eos on K+ yield !
QMD transport calculations • C. Fuchs et al., Phys.Rev.Lett. 86 (2001) 1974
The compressibility of nuclear matter Experiment: C. Sturm et al., Phys. Rev. Lett. 86 (2001) 39 Theory: QMD C. Fuchs et al., Phys. Rev. Lett. 86 (2001) 1974 IQMD Ch. Hartnack, J. Aichelin, J. Phys. G 28 (2002) 1649 Figure by C. Fuchs soft equation-of-state: k = 200 MeV
L(1405) K- K- N-1 K mesons in dense matter G.E Brown, C.H. Lee, M. Rho, V. Thorsson, Nucl. Phys. A 567 (1994) 937 T. Waas, N. Kaiser, W. Weise, Phys. Lett. B 379 (1996) 34 J. Schaffner-Bielich, J. Bondorf, I. Mishustin , Nucl. Phys. A 625 (1997) In-medium spectral functions of K-, (1405) and (1385) M. Lutz, C. Korpa, Nucl. Phys. A 700 (2002) 309 self-consistent coupled channel calculation (s,p,d waves)
In-medium modifications of K+ mesons Data: M. Menzel et al., KaoS Collab., Phys. Lett. B 495 (2000) 26 K. Wisniewski et al., FOPI Collab., Eur. Phys. J A 9 (2000) 515 Figure by C. Fuchs
K+ azimuthal emission pattern from A+A collisions Data: Y. Shin et al., Phys. Rev. Lett. 81 (1998) 1576 F. Uhlig et al., Phys.Rev.Lett. 95 (2005) 012301 Theory: A. Larionov, U. Mosel, nucl-th/0504023 Evidence for repulsive K+N interaction !
Ni+Ni at 1.93 AGeV: π, K+ and K- azimuthal distributions F. Uhlig et al., Phys. Rev. Lett. 95 (2005) 012301 3.8 fm < b < 6.4 fm 0.4 < y/ybeam <0.6 0.2 GeV < p┴< 0.8 GeV IQMD Calculation:C. Hartnack et al.
Au+Au 1.5 AGeV semi-central collisions (b > 6.4 fm) K+ and K- azimuthal angular distributions M. Płoskon, PhD Thesis 2005 dN(φ)/φ 1 + 2v1cos(φ) + 2v2cos(2φ) + ...
Elliptic flow of K+ and K- mesons: Comparison to off-shell transport calculations and in-medium spectral functions Data: M. Płoskon, PhD Thesis, Univ. Frankfurt 2005 Off-shell transport calculations: W. Cassing et al., NPA 727 (2003) 59, E. Bratkovskaya, priv. com. Coupled channel G-Matrix approach (K- spectral functions): L. Tolos et al., NPA 690 (2001) 547 dN(φ)/φ 1 + 2v1cos(φ) + 2v2cos(2φ) + ...
The Kaon Spectrometer at SIS (1991 – 2002) Collaboration GSI Darmstadt: P. Koczoń, F. Laue, M. Płoskon, E. Schwab, P Senger, C. Sturm TU Darmstadt: A. Förster, S. Lang, H. Oeschler, A. Schmah, F. Uhlig Univ. Frankfurt: Y. Shin, T. Schuck, H. Ströbele Univ. Marburg: I. Böttcher, B. Kohlmeyer, M. Menzel Univ. Kraków: M. Dębowski, G. Surówka,W. Waluś FZ Rossendorf: F. Dohrmann, E. Grosse, L. Naumann, W. Scheinast, W. Wagner
Towards higher baryonic densities Ch. Fuchs, Tübingen
Transport calculations: baryon and energy densities Baryon density in central cell (Au+Au, b=0 fm): QGSM: Cascade, hadrons + resonances + strings C. Fuchs, V. Toneev
“Trajectories” from UrQMD H. Stöcker nucl-th/0506013
“Trajectories” from 3 fluid hydrodynamics Hadron gas EOS: Y. Ivanov, V. Russkikh, V.Toneev nucl-th/0503088 early phase (first 2 fm/c) not in thermodynamic equilibrium !
critical point hadrons Q G P coexistence phase Intriguing observations by NA49 @ CERN-SPS Pb+Pb ? next steps: confirmation of NA49 → Low energy run at RHIC ? comprehensive experimental study → CBM @ FAIR
Diagnostic probes of compressed baryonic matter U+U 23 AGeV
Compressed Baryonic Matter: physics topics and observables Probing the equation-of-state at high B Observables: collective flow of hadrons, particle production at threshold energies (open charm) Search for a deconfined phase at high B enhanced strangeness production ? Observables: K, , , , anomalous charmonium suppression ? Observables:charmonium (J/ψ, ψ'), open charm (D0, D) Search for chiral symmetry restoration at high B in-medium modifications of hadrons Observables: , , e+e- , open charm, ..... Search for the 1. order phase transition & the critical endpoint Observable: event-by-event fluctuations (K/π, pT, ...)
Experimental program of CBM: Observables: Penetrating probes:, , , J/ → e+e- (μ+μ-) Strangeness:K, , , , , Open charm: Do, D, Ds, c, global features: collective flow, fluctuations, ..., exotica Systematic investigations: A+A collisions from 8 to 45 (35) AGeV, Z/A=0.5 (0.4) p+A collisions from 8 to 90 GeV p+p collisions from 8 to 90 GeV Beam energies up to 8 AGeV: HADES Detector requirements Large geometrical acceptance (azimuthal symmetry !) good hadron and electron identification excellent vertex resolution high rate capability of detectors, FEE and DAQ Large integrated luminosity: High beam intensity and duty cycle, Available for several month per year
Meson production in central Au+Au collisions W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745 SIS100/ 300 SIS18
The CBM Experiment Silicon Tracking System (STS) Radiation hard Silicon (pixel/strip) Tracking Systemin a magnetic dipole field Electron detectors: RICH & TRD & ECAL: pion suppression better 104 Hadron identification: TOF-RPC Measurement of photons, π, η, and muons: electromagn. calorimeter (ECAL) High speed data acquisition and trigger system
Experimental challenges Central Au+Au collision at 25 AGeV: URQMD + GEANT4 160 p, 400 -, 400 +, 44 K+, 13 K-,.... 107 Au+Au reactions/sec (beam intensities up to 109 ions/sec, 1 % interaction target) determination of (displaced) vertices with high resolution ( 50 m) identification of electrons and hadrons
CBM 8 – 45 AGeV and outlook HADES 2 – 8 AGeV
CBM Collaboration : 40 institutions, > 350 Members Croatia: RBI, Zagreb China: Wuhan Univ. Hefei Univ. Cyprus: Nikosia Univ. Czech Republic: CAS, Rez Techn. Univ. Prague France: IReS Strasbourg Hungaria: KFKI Budapest Eötvös Univ. Budapest India: VECC Kolkata Korea: Korea Univ. Seoul Pusan National Univ. Norway: Univ. Bergen Germany: Univ. Heidelberg, Phys. Inst. Univ. HD, Kirchhoff Inst. Univ. Frankfurt Univ. Kaiserslautern Univ. Mannheim Univ. Münster FZ Rossendorf GSI Darmstadt Poland: Krakow Univ. Warsaw Univ. Silesia Univ. Katowice Portugal: LIP Coimbra Romania: NIPNE Bucharest Russia: IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg Kurchatov Inst., Moscow LHE, JINR Dubna LPP, JINR Dubna LIT, JINR Dubna MEPHI Moscow Obninsk State Univ. PNPI Gatchina SINP, Moscow State Univ. St. Petersburg Polytec. U. Ukraine: Shevshenko Univ. , Kiev
Summary and outlook Towards highest baryon densities (3-10 ρ0): • Search for: • first order phase transition • critical endpoint • chiral symmetry restoration • Probes: • strangeness, charm, vector mesons, flow, • correlations, fluctuations, ..... • Comprehensive studies with CBM @FAIR • Complementary to RHIC and ALICE Probing dense baryonic matter (1-3 ρ0): Excitation function of K+ production in A+A collisions: The nuclear matter equation-of-state is soft ( K 200 MeV) Yield and elliptic flow of K+ mesons: The in-medium potential of K+ mesons is repulsive Yield and elliptic flow of K- mesons: Quantitative interpretation of data requires off-shell transport calculations and in-medium spectral functions
Theoretical prediction of meson production in central Au+Au collisions Hadron String Dynamics transport calculation W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745 SIS100/ 300
Off-shell transport calculations L. Tolos et al., NPA 690 (2001) 547 coupled channel G-Matrix approach: K- spectral functions off-shell HSD: W. Cassing et al., NPA 727 (2003) 59