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Compressed baryonic matter -Experiments at GSI and at FAIR
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
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 II1.4M Mcore 2M
neutron star
M 15M
Supernova IIaM 2M
black hole
The Crab nebula ...... and his pulsating heartIn 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 about7000 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 byS. Thorsett, Princeton Univ. 1997
more than 1500 pulsars known
best determined mass:M = (1.4411 0.00035)M
(Hulse-Taylor-Pulsar)
shortest rotation period:1.557 ms (PSR 1937+21)
Strongly interacting matter in neutron stars
F. Weber J.Phys. G27 (2001) 465
neutron star core withcorrelated 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 universeAu-nucleus: R 7 fm, V 1400 fm3
Nucleon: R 0.8 fm, V 2 fm3 200 Nucleons: V 400 fm3
At 3 – 4 ρ0: nucleons overlap
time
temperature
15 billion years
1 billion years
300.000 years
3 minutes
1 millisecond
3 K
20 K
109 K
1012 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 ρ0)
• neutron star stability (ρ > 3 ρ0)
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 matterfrom 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 matterfrom collective flow of particles
dN/d1 + 2v1cos + 2v2 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
udsn
du
udd
su
K+
udu
uu
uds
su
p
K-K-
absorption
uds
n
p
udd s
u
K+
ddu
nudu
udu
udu
n
p
udd
su K+
su
p
K
ddu n
Idea: K+ yield baryon density ρ compressibility κ
Au+Au at 1 AGeV (RBUU): soft eos ρmax 2.9 ρ0 K+ yield uphard eos ρmax 2.4 ρ0 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 matterExperiment: C. Sturm et al., Phys. Rev. Lett. 86 (2001) 39Theory: 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) 012301
Theory: A. Larionov, U. Mosel, nucl-th/0504023
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)
eK +e
K- condensation in neutron stars (e- K- +νe, 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) 1640M. 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) 012301
Ni+Ni at 1.93 AGeV: π, K+ and K- azimuthal distributions
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.
dN(φ)/φ 1 + 2v1cos(φ) + 2v2cos(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-
N-1
0
2
4
6
8
10
20
1.50
0
0.50
A(s
) [M
eV-1]
p=0 MeV/c
A(s
) [M
eV-1]
20
1.50
0
0.50
p=150 MeV/c
0.2 0.4 0.6 0.80
2
4
6
8
10
20
1.50
0
0.50
s1/2
[GeV]
p=300 MeV/c
s1/2
[GeV]
0.2 0.4 0.6 0.8
20
1.50
0
0.50
p=500 MeV/c
L. Tolos et al., NPA 690 (2001) 547coupled channel G-Matrix approach:
Off-shell transport calculations (HSD code)W. Cassing et al., NPA 727 (2003) 59
delayed K- production via strangeness exchangereactions which areenhanced due to in-mediummodifications of hyperons
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 functionsData: M. Płoskon, PhD Thesis, Univ. Frankfurt 2005Off-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 ρ0) 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)
CollaborationGSI 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