Compressed baryonic matter - Experiments at GSI and at FAIR 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 Peter Senger (GSI) Dense Matter In Heavy Ion Collisions and Astrophysics, August 2006, Dubna

Birth and death of stars M   8M  red giant white dwarf 8M   M  15M  Supernova II 1.4M   M core  2M  neutron star M  15M  Supernova IIa M  2M  black hole

The Crab nebula and his pulsating heart In 1054 chinese astronomers observed a “visiting star”: As bright as the full moon for 1 month glowing remnant of a core collapse supernova: distance from earth about 7000 light years diameter about ca. 10 light years, expansion about 1000 Km/s. 1968/69: discovery of a pulsating radiation source (30 Hz) Rotating neutron star with strong magnetic field Synchrotron radiation from high energy electrons

Supernova 1987: near the Tarantula nebula in the Large Magellanic Cloud no pulsar observed up to now !

Measured neutron star masses Compiled by S. Thorsett, Princeton Univ more than 1500 pulsars known best determined mass: M = (  )M  (Hulse-Taylor-Pulsar) shortest rotation period: ms (PSR )

Strongly interacting matter in neutron stars F. Weber J.Phys. G27 (2001) 465 qq neutron star core with correlated qq pairs: color superconductivity nucleon star: kaon condensate “Strangeness" of dense matter ? In-medium properties of hadrons ? Compressibility of nuclear matter? Deconfinement at high baryon densities ?

Extreme states of strongly interacting matter baryons hadrons partons Compression + heating = quark-gluon matter (pion production) Neutron stars Early universe Au-nucleus: R  7 fm, V  1400 fm 3 Nucleon: R  0.8 fm, V  2 fm Nucleons: V  400 fm 3 At 3 – 4 ρ 0 : nucleons overlap

time temperature 15 billion years 1 billion years years 3 minutes 1 millisecond 3 K 20 K 10 9 K K Distanz 3000 K The evolution of matter in the universe The soup of the first millisecond: quarks, antiquarks, electrons, positrons, gluons, photons Where are the antiparticles ?

Mapping the QCD phase diagram with heavy-ion collisions

High energy Au+Au collisions in transport calculations B. Friman, W. Nörenberg, V.D. Toneev Eur. Phys. J. A3 (1998) 165 For beam energies < 50 A GeV fireball lifetimes > 3 fm/c

The quest for the equation-of-state of dense nuclear matter Info on the EOS is relevant for: dynamics of core-collapse supernova (ρ < 3 ρ 0 ) neutron star stability (ρ > 3 ρ 0 ) Experimental approaches: pion yield in A+A collisions (R.Stock) collective flow in A+A collisions kaon production in A+A collisions

directed transverse flow P. Danielewicz, R. Lacey, W.G. Lynch, Science 298 (2002) 1592 Determination of the Equation of State of dense matter from collective flow of particles

elliptic flow P. Danielewicz, R. Lacey, W.G. Lynch, Science 298 (2002) 1592 Determination of the Equation of State of dense matter from collective flow of particles dN/d  1 + 2v 1  cos  + 2v 2 cos2 

P. Danielewicz, R. Lacey, W.G. Lynch, Science 298 (2002) 1592 Zero temperature EOS shaded areas are consistent with experimental flow results pressure versus density No firm conclusion on EOS, problems due to:  momentum dependent interactions  no cluster formation in transport

Kaon production in Au+Au collisions at 1 AGeV K + mesons probe high densities

The creation of strange mesons udsuds n dudu  uddudd susu  K+K+ uduudu  uuuu  udsuds susu p K-K- K - absorption udsuds n p uddudd susu  K+K+ dduddu n uduudu uduudu uduudu n p uddudd susu K+K+ susu p KK dduddu n

Idea: K + yield  baryon density ρ  compressibility κ Au+Au at 1 AGeV (RBUU): soft eos  ρ max  2.9 ρ 0  K + yield up hard eos  ρ max  2.4 ρ 0  K + yield down but: in C+C no influence of eos on K + yield ! 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

C. Fuchs et al., Phys.Rev.Lett. 86 (2001) 1974 QMD transport calculations

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:  = 200 MeV Figure by C. Fuchs

K mesons in dense matter (I) 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) How to measure in-medium modifications of kaons in heavy-ion collisions?  yield at subthreshold beam energies  repulsive K + N and attractive K - N potential: angular distributions

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

Data: Y. Shin et al., Phys. Rev. Lett. 81 (1998) 1576 F. Uhlig et al., Phys.Rev.Lett. 95 (2005) Theory: A. Larionov, U. Mosel, nucl-th/ Evidence for repulsive K + N interaction ! K + azimuthal emission pattern from A+A collisions

K mesons in dense matter (II) 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) e   K  + e K - condensation in neutron stars ( e -  K - +ν e, n  p + K - ) ? G.E. Brown, H.A. Bethe, Astrophys. Jour. 423 (1994) 659 G.Q.Li, C.H. Lee, G.E. Brown, Nucl. Phys. A 625 (1997)

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 Parameterization: A.Sibirtsev, W. Cassing, C.M. Ko, Z. Phys. A 258 (1997) 101 Enhancement due to:  Strangeness exchange reactions   K - N ?  Attractive in-medium K - N potential ?

F. Uhlig et al., Phys. Rev. Lett. 95 (2005) Ni+Ni at 1.93 AGeV: π, K + and K - azimuthal distributions 3.8 fm < b < 6.4 fm 0.4 < y/y beam < GeV < p ┴ < 0.8 GeV IQMD Calculation: C. Hartnack et al.

dN(φ)/φ  1 + 2v 1 cos(φ) + 2v 2 cos(2φ) +... Au+Au 1.5 AGeV semi-central collisions (b > 6.4 fm) K + and K - azimuthal angular distributions M. Płoskon, PhD Thesis 2005

K mesons in dense matter (III): 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)  (1405) K-K- K-K- N -1 L. Tolos et al., NPA 690 (2001) 547 coupled channel G-Matrix approach:

Off-shell transport calculations (HSD code) W. Cassing et al., NPA 727 (2003) 59 delayed K - production via strangeness exchange reactions which are enhanced due to in-medium modifications of hyperons

dN(φ)/φ  1 + 2v 1 cos(φ) + 2v 2 cos(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

Summary and outlook (part I) Probing dense baryonic matter (1-3 ρ 0 ) with kaons: 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

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