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Kaon production in nucleus-nucleus collisions. Peter Senger (GSI). Probing dense baryonic matter with kaons: The nuclear equation-of-state In medium properties of strange mesons. XI International Conference on Hypernuclear and Strange Particle Physics, October 10 – 14, Mainz, Germany.
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Kaon production in nucleus-nucleus collisions Peter Senger (GSI) Probing dense baryonic matter with kaons: The nuclear equation-of-state In medium properties of strange mesons XI International Conference on Hypernuclear and Strange Particle Physics, October 10 – 14, Mainz, Germany
Strongly interacting matter in neutron stars “Strangeness" of dense matter ? In-medium properties of hadrons ? Compressibility of nuclear matter? Deconfinement at high baryon densities ? F. Weber J.Phys. G27 (2001) 465
Kaon production in Au+Au collisions at 1 AGeV u d d u d s L n d u s u K+ p+ K+ mesons probe high densities
t Particle identification Acceptance Au + Au 1 AGeV 1. Minumum bias trigger 2. Kaon trigger (TOF & Cherenkov) 3. Kaon trigger & tracking& 2xTOF lab = 32,40,50,60o B = 0.6, 0.9, 1.4 Tesla
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 hard eos ρmax 2.4 ρ0 K+ yield 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 soft equation-of-state: k = 200 MeV
Towards higher baryonic densities Ch. Fuchs, Tübingen
Meson production in central Au+Au collisions W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745 SIS100/ 300 SIS18 CBM@FAIR
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
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 !
u d s u d u p u u s u K- p0 K-absorption Enhanced antikaon production in A+A collisions F. Laue, C. Sturm et al., Phys. Rev. Lett. 82 (1999) 1640 M. Menzel et al., Phys. Lett. B 495 (2000) 26 In-medium effects: modification of masses and cross sections ? strangeness exchange reactions ?
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) + ...
Strangeness production in proton - nucleus collisions p + C K+ + X (1.6, 2.5, 3.5 GeV) p + C K- + X (2.5, 3.5 GeV) p + Au K+ + X (1.6, 2.5, 3.5 GeV) p + Au K- + X (2.5, 3.5 GeV) W. Scheinast et al., Phys. Rev. Lett. 96 (2006) 072301
Comparison of p+A data to transport calculation K+ K- UK≈ - 80 /0 MeV Transport calculation: H. W. Barz et al., Phys.Rev. C68 (2003) 041901 Important channel: Strangeness exchange + N N + N + K—
Summary 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 in A+A collisions: The in-medium potential of K+ mesons is repulsive Yield of K- mesons proton-nucleus collisions: Evidence for a K-N in-medium potential of UK ≈ - 80 /0 MeV Yield and elliptic flow of K- mesons in A+A collisions: Quantitative interpretation of data requires off-shell transport calculations and in-medium spectral functions
The Kaon Spectrometer 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
Kaons and antikaons from Au +Au collisions at 1.5 AGeV A. Förster et al., Phys. Rev. Lett. 91 (2003)152301 different freeze-out conditions for K+ and K- !
Kaons and antikaons from Ni+Ni collisions at 1.93 AGeV F. Uhlig et al., Phys. Rev. Lett. 95 (2005) 012301
The evolution of strangeness production L. Tolos et al., NPA 690 (2001) 547 coupled channel G-Matrix approach: spectral functions off-shell HSD: W. Cassing et al., NPA 727 (2003) 59