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

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 1987near the Tarantula nebula

in the Large Magellanic Cloud

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

qq

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:

• neutron star stability (ρ > 3 ρ0)

• dynamics of core-collapse supernova (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 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

P. Danielewicz, R. Lacey, W.G. Lynch, Science 298 (2002) 1592

Zero temperature EOS

shaded areas are consistent with experimental flow results

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)

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:

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

Off-shell transport calculations (HSD code)

W. Cassing et al., NPA 727 (2003) 59

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