Presentation on theme: "The Physics of Dense Nuclear Matter Introduction Status Near future Perspectives at FAIR Joachim Stroth Univ. Frankfurt / GSI."— Presentation transcript:
The Physics of Dense Nuclear Matter Introduction Status Near future Perspectives at FAIR Joachim Stroth Univ. Frankfurt / GSI
NuPPEC meeting, Paris, November 2004Joachim Stroth2 Dense nuclear matter in the laboratory What are the properties of dense nuclear matter? Dense matterFreeze-out First chance collisions Its macroscopic properties depend on the microscopic structure! → Hadron physics (in-medium)
NuPPEC meeting, Paris, November 2004Joachim Stroth3 The physics case J. Wambach et al. Does the quark model provide the right description of hadrons? What is the relevant excitation spectrum as the matter density increases? What is the role of chiral symmetry breaking in the generation of hadron masses? Where are the limits of hadronic existence? Matter properties (EOS) of compact stars!
NuPPEC meeting, Paris, November 2004Joachim Stroth4 Pionic bound states are clearly observed. The measured binding energies evidence a reduced expectation value of the Chiral Condensate at nuclear ground state density. Pionic atoms Fragment separator at GSI used as high-resolution forward spectrometer Collaboration Nava, GSI, Munich, Jülich, Tokyo, Niigata, RIKEN Mesonic Atoms Experiments combine techniques from hadron and heavy ion physics. (inelastic NN reaction and pick-up). Pions with favorable momentum are trapped in the Coulomb-field of the heavy Nucleus.
NuPPEC meeting, Paris, November 2004Joachim Stroth AGeV central collisions 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 Transport calculations: G.Q. Li & G.E. Brown In-medium mass of strange mesons In-medium potential of strange mesons should lead to shift a of the effective kaon mass! Indication observed in heavy ion reaction at the SIS18, GSI by KAOS and FOPI. K-K- K+K+ KAOS results selected among the 10 most important physics results in 1998 (APS)
NuPPEC meeting, Paris, November 2004Joachim Stroth6 Kaonic bound states Exotic bound states with strangeness Attractive K - N potential results in additional binding Production mechanisms presently uncertain, might be populated in HI collisions but probably also in induced reactions.
NuPPEC meeting, Paris, November 2004Joachim Stroth7 preliminary 12 C+ 12 C 2 AGeV e+ e- 208 Pb -- n HADES High Acceptance Dielectron Spectrometer Low-mass vector mesons Detected by electron pair reconstruction (penetrating probes). Spectrometer with high invariant mass resolution and high rate capability. operational since 2001 at GSI. Beams of: –Pions –Protons –Nuclei
NuPPEC meeting, Paris, November 2004Joachim Stroth8 Primary Beams /spill; GeV/u; 238 U 28+ Factor over present in intensity 2(4)x10 13 /spill 30 GeV protons /spill 238 U 73+ up to 35 GeV/u up to 90 GeV protons Secondary Beams Broad range of radioactive beams up to GeV/u; up to factor in intensity over present Antiprotons GeV Key Technical Features Cooled beams Rapidly cycling superconducting magnets Storage and Cooler Rings Radioactive beams e - – A (or Antiproton-A) collider stored and cooled GeV antiprotons UNILAC SIS SIS 100/300 International FAIR Project: SIS300 CBM
NuPPEC meeting, Paris, November 2004Joachim Stroth9 The energy scan at SPS (NA94) Exiting observations at an energy of around 30 AGeV →Relative enhancement of strangeness →Not explained by transport calculations and statistical model SPS heavy ion program suspended due to priority for LHC CERN SPS-C: "The search for the critical point is of high importance for the understanding of QCD..... Respective proposals can be accepted for a time period after 2008". Integrated Luminosity ? NA49, M. Gazdzicki et al. Fluctuations due to approach of the critical point ??
NuPPEC meeting, Paris, November 2004Joachim Stroth10 The Compressed Baryonic Matter program CBM Detector Heavy ion collisions at interaction rates of up to 10 7 Hz Excitation functions from 2 to 35 GeV/u Experimental goal of the CBM collaboration: Systematic investigation of dense baryonic matter using penetrating and rare probes! Observables: Penetrating probes: , , , J/ Strangeness: K, , , , , Open charm: D o, D Hadrons ( p, π), exotica HADES Needs large integrated luminosity: High beam intensity and duty cycle, available for several month per year
NuPPEC meeting, Paris, November 2004Joachim Stroth11 Physics program of CBM SIS18 SIS300 ûFluctuations in the strangeness production Signal for the critical point ûLow mass electron pairs Probe the in-medium structure of hadrons ûNear threshold open-charm production Analogy to strangeness at 1-2- AGeV ûCharmonium production Sensitive to the early state of the matter
NuPPEC meeting, Paris, November 2004Joachim Stroth12 The physics community FOPI upgrade→ heavy ion program world-wide unique European collaboration + Japan: 50 physicist Bucharest, Budapest, Clermont-Ferrand, Darmstadt, Dresden, Florence, Heidelberg, Moscow, Seoul, Strasbourg, Warszawa, Zagreb HADES → heavy ions world-wide unique (elementary JLAB, KEK) European collaboration: 120 physicist Bratislava, Catania, Dubna, Frankfurt, Giessen, Milano, Moscow, Garching, Nicosia, Orsay, Rez, Dresden, Santiago de Compostela, Valencia CBM → RHIC low energy program uncertain, SPS suspended International collaboration: >300 physicist Further interest by people from former NA49 experiment – CERN proposal ? Theory→ Microscopic transport essential Smaller groups at different universities FP6 I3HP
NuPPEC meeting, Paris, November 2004Joachim Stroth13 Motivation: II T.D. Lee „The challenge for the next century physics is: explain confinement and broken (chiral) symmetry“ T.D. Lee F. Wilczek „But perhaps the most interesting and surprising thing about QCD at high density is that, by thinking about it, one discovers a fruitful new perspective on the traditional problem of confinement and chiral-symmetry breaking”. F. Wilczek
NuPPEC meeting, Paris, November 2004Joachim Stroth14