Strange particles and neutron stars - experiments at GSI Outline: Probing dense baryonic matter (1-3...
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Transcript of Strange particles and neutron stars - experiments at GSI Outline: Probing dense baryonic matter (1-3...
Strange particles and neutron stars -experiments at 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
Peter Senger (GSI)
International Symposium on Heavy-Ion Physics, April 2-6, 2006, Frankfurt
Strongly interacting matter in neutron stars
F. Weber J.Phys. G27 (2001) 465
nucleon star: kaon condensate
“Strangeness" of dense matter ?In-medium properties of hadrons ?Nuclear matter equation of state ?
Deconfinement at high baryon densities ?
color superconductor ?
Kaon production in Au+Au collisions at 1 AGeV
K+ mesons probe high densities
udsn
du
udd
su
K+
udu
uu
uds
su
p
K-K-
absorption
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 matterG.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)
M. Lutz, C. Korpa, Nucl. Phys. A 700 (2002) 309 self-consistent coupled channel calculation (s,p,d waves)
In-medium spectral functionsof K-, (1405) and (1385)
(1405)
K- K-
N-1
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
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
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
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
Towards higher baryonic densities
Ch. Fuchs, Tübingen
Baryon density in central cell (Au+Au, b=0 fm):QGSM: Cascade, hadrons + resonances + strings
Transport calculations: baryon and energy densities
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 inthermodynamic equilibrium !
Intriguing observations by NA49 @ CERN-SPS
coexistence phase
hadronsQGP
critical point
next steps:confirmation of NA49 → Low energy run at RHIC ?comprehensive experimental study → CBM @ FAIR
?
Pb+Pb
Diagnostic probes of compressed baryonic matter
U+U 23 AGeV
Compressed Baryonic Matter: physics topics and observables
Search for chiral symmetry restoration at high B
in-medium modifications of hadrons
Observables: , , e+e- , 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)
Probing the equation-of-state at high B
Observables: collective flow of hadrons, particle production at threshold energies (open charm)
Search for the 1. order phase transition & the critical endpoint Observable: event-by-event fluctuations (K/π, pT, ...)
Observables:Penetrating probes: , , , J/ → e+e- (μ+μ-)Strangeness: K, , , , , Open charm: Do, D, Ds, c,
global features: collective flow, fluctuations, ..., exotica
Experimental program of CBM:
Systematic investigations:A+A collisions from 8 to 45 (35) AGeV, Z/A=0.5 (0.4) p+A collisions from 8 to 90 GeVp+p collisions from 8 to 90 GeVBeam energies up to 8 AGeV: HADES
Large integrated luminosity:High beam intensity and duty cycle,Available for several month per year
Detector requirementsLarge geometrical acceptance (azimuthal symmetry !)good hadron and electron identificationexcellent vertex resolutionhigh rate capability of detectors, FEE and DAQ
SIS18 SIS100/
300
Meson production in central Au+Au collisionsW. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745
Radiation hard Silicon (pixel/strip) Tracking System in 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
The CBM Experiment
Silicon Tracking System (STS)
Experimental challenges
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
Central Au+Au collision at 25 AGeV:URQMD + GEANT4
160 p, 400 -, 400 +, 44 K+, 13 K-,....
HADES2 – 8 AGeV
CBM8 – 45 AGeV
and outlook
CBM Collaboration : 40 institutions, > 350 MembersCroatia: RBI, Zagreb
China:Wuhan Univ.Hefei Univ.
Cyprus: Nikosia Univ.
Czech Republic:CAS, RezTechn. Univ. Prague
France: IReS Strasbourg
Hungaria:KFKI BudapestEötvös Univ. Budapest
India:VECC Kolkata
Romania: NIPNE Bucharest
Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. PetersburgKurchatov Inst., MoscowLHE, JINR DubnaLPP, JINR DubnaLIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP, Moscow State Univ. St. Petersburg Polytec. U.
Ukraine: Shevshenko Univ. , Kiev
Korea:Korea Univ. SeoulPusan National Univ.
Norway:Univ. Bergen
Germany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. FrankfurtUniv. KaiserslauternUniv. Mannheim Univ. MünsterFZ RossendorfGSI Darmstadt
Poland:Krakow Univ.Warsaw Univ.Silesia Univ. Katowice
Portugal: LIP Coimbra
SummaryProbing 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
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 @FAIRComplementary to RHIC and ALICE
and outlook
SIS100/ 300
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
Off-shell transport calculations
off-shell HSD: W. Cassing et al., NPA 727 (2003) 59
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:K- spectral functions