1 / 23

Nuclear Matter Physics NICA

Nuclear Matter Physics NICA. s. s. u. d. Λ. s. ?. u. Λ. P. Senger, GSI. Outline  The equation-of-state of nuclear matter at high densities  Search for the deconfinement phase transition  Search for (short-lived) strange matter

xenos
Télécharger la présentation

Nuclear Matter Physics NICA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nuclear Matter Physics NICA s s u d Λ s ? u Λ P. Senger, GSI Outline  The equation-of-state of nuclear matter at high densities  Search for the deconfinement phase transition  Search for (short-lived) strange matter  Hadrons in dense nuclear matter: Dilepton spectroscopy NICA Roundtable Workshop IV: Physics at NICA, JINR, Dubna, Russia, Sept. 9-12, 2009

  2. The QCD Phase diagram: facts and speculations A. Andronic et al., Phys. Lett. B 673 (2009). Experimental results: Freeze-out curve (T, μB) Tfo = 161 ±4 MeV at (μB=0) partonic matter at RHIC energies L-QCD Predictions: TC= 151 ± 3 ± 3 MeV (chiral PT) TC= 175 ± 2 ± 4 MeV (deco. PT) (Z. Fodor, arXiv:0712.2930 hep-lat) TC= 192 ± 7 ± 4 MeV (chiral & deco. PT) (F. Karsch, arXiv:0711.0661 hep-lat) crossover transition at μB=0 (Z. Fodor, arXiv:0712.2930 hep-lat) 1. order phase transition with critical endpoint at μB > 0 ? Exploring the QCD phase diagram at large μB with heavy-ion collisions: RHIC energy-scan:search for QCD-CP with bulk observables NA61@SPS: search for QCD-CP with bulk observables MPD@NICA: search for the QCD mixed phase CBM@FAIR: scan of the phase diagram with bulk and rare observables

  3. Messengers from the dense fireball ? UrQMD transport calculation U+U 23 AGeV μ+ μ- Up to date only freeze-out probes have been measured in A+A collisions at 2 - 30 AGeV

  4. Particle multiplicity x branching ratio for min. bias Au+Au collisions at 25 GeV (√s= 7.1 GeV) (from HSD and thermal model) SPS Pb+Pb 30 A GeV NICA ?

  5. The equation-of-state of (symmetric) nuclear matter Equation of state: P = dE/dVT=const V = A/ρ dV/ dρ = - A/ρ2 P = ρ2 d(E/A)/dρT=const C. Fuchs, Prog. Part. Nucl. Phys. 56 (2006) 1 T=0: E/A = 1/r  U (r)dr Effective NN-potential: U(r)=ar+brg • E/A(ro) = -16 MeV • d(E/A)(ro)/dr = 0 • Compressibility: k = 9r2 d2(E/A)/ dr2 k = 200 MeV: "soft" EOS k = 380 MeV: "stiff" EOS

  6. Probing the nuclear equation-of-state: proton collective flow P. Danielewicz, R. Lacey, W.G. Lynch, Science 298 (2002) 1592 K = 170 – 210 MeV K = 170 – 380 MeV Within microscopic transport models the collective flow is sensitive to:  The nuclear matter equation of state  In-medium nucleon-nucleon cross sections  Momentum dependent interactions Transverse in-plane flow: Elliptic flow: F = d(px/A)/d(y/ycm) dN/dF  (1 + 2v1cosF + 2v2 cos2F)

  7. ? κ = 200 MeV (sub)threshold production of K+ mesons κ = 380 MeV

  8. Exploring the "nuclear" EOS at 3ρ0 < ρ < 7ρ0 with (sub)threshold production of multistrange hyperons Measure the excitation function of (multi-strange) hyperon production in heavy-ion collisions from 2 - 15 AGeV: Direct production: NN  Λ0Λ0 NN (Ethr = 7.1 GeV) NN +- NN (Ethr = 9.0 GeV) NN +- NN (Ethr = 12.7 GeV) Production via multiple collisions: Hyperons (s quarks): 1. NN K+Λ0N,NN  K+K-NN, 2.Λ0Λ0- p,Λ0K-- 0 3.Λ0 -- n,-K--- Antihyperons (anti-s quarks): 1. Λ0 K++0 , 2. +K+++. AGS SPS Measure excitation function for multi-strange hyperons in light and heavy collision systems

  9. Signatures for a phase transition at SPS ? inverse slope parameter [NA49, PRC 77, 024903 (2008)] Experimental data exhibit structures in excitation functions of observables at low SPS energies:  limiting freeze-out temperature  step in collective flow  maximum in the strangeness/entropy ratio chemical freeze-out temperature A. Andronic et al., Nucl. Phys. A 772, 167 (2006). A. Andronic et al., Phys. Lett. B 673 (2009). 28

  10. Signatures for partonic collectivity at RHIC  Large elliptic flow  elliptic flow scales with number of participant quarks  suppression of high momentum hadrons (jet quenching) Energy scan at RHIC (STAR): Measure excitation function of v2 versus pT for π, K, p, φ, Λ, Ξ,Ω

  11. Search for the QCD critical endpoint: Measuring net baryon density fluctuations via multistrange hyperons Production via multiple collisions: Hyperons (s quarks): 1. pp K+Λ0p,NN  K+K-NN, 2.Λ0Λ0- p,Λ0K-- 0 3.Λ0 -- n,-K--- Antihyperons (anti-s quarks): 1. pp  Λ0Λ0 pp 2. Λ0 K++0 , 3. +K+++. Search for structures in the excitation function of Ω/Λ

  12. Identification of hyperons in heavy-ion collisions with tracking detectors via decay topology (no PID) -- (uds) (dss) (sss) Example: central Au+Au collisions at 6 AGeV (CBM):

  13. Hypernuclei and metastable multi-strange objects H. Stöcker et al., Nucl. Phys. A 827 (2009) 624c

  14. Being prepared for exotica: experimental reconstruction of a multistrange di-baryon p p- L2 p (X0L)b L1 p- Signal: strange dibaryon (0)b   (cτ=3cm) M= 10-6, BR = 5% Background: Au+Au @ 25 AGeV 32  per central event 11  reconstructable

  15. e+, μ+ r e-, μ- Looking into the fireball …  n  p p  ++ K … using penetrating probes: short-lived vector mesons decaying into electron-positron pairs

  16. Dilepton measurements in heavy-ion collisions CERES 2000: 159 AGeV Pb+Au beam intensity: 106 ions / spill 1 spill = 4 s beam and 15 s pause targets: 13 x 25 μm Au (~1 % interaction) trigger: 8% most central Event rate = 470 / spill (~ 25 Hz = 15 Mio events/week) 5-week-long run in Oct.–Nov. 2003 ~ 4 × 1012 ions delivered in total = 1.3 × 106 ions/s ~ 20 kHz reaction rate

  17. Search for the modification of hadron properties via dilepton measurements Calculations: H. van Hees, R. Rapp, arXiv:0711.3444v1 [hep-ph] Data: CERES Data: NA60 e+e- μ+μ- Electrons: access to Minv< 200 MeV/c2 Muons: better statistics (trigger)

  18. Radial flow as function of particle mass: probing the early phase of the fireball evolution R. Arnaldi et al., (NA60), PRL 100 (2008) 022302 N. Xu, Int. J. Mod. Phys. E16 (2007) 715 M < 1 GeV/c2: radial flow generated in the late hadronic phase M > 1 GeV/c2: messengers from the early partonic phase ?

  19. Single electron spectra Typical background in electron measurements Example: Au+Au 25 A GeV, fixed target (1%) (x104)

  20. Electron identification: RICH & TRD & TOF RICH ring radii ΔE in TRD momentum (GeV) momentum (GeV)

  21. Summary I: Estimated particle yields Example: min. bias Au+Au collisions at √sNN = 7.1 GeV Assumption: max. NICA luminosity L = 1027cm-2s-1

  22. Summary II: Detector requirements The CBM-MPD consortium (coordinator Y. Murin): Joint R&D on a prototype Silicon tracker for FAIR and NICA

More Related