Exploring the QCD Phase Diagram at High Baryon Densities: From SPS to FAIR Claudia Höhne, GSI Darmstadt QCD phase diagram results from SPS and RHIC CBMphysics topics and observables feasibility studies and R&D

Claudia Höhne ISHIP 2008, GSI, November QCD phase diagram at high baryon densities [F.Karsch, Z. Fodor, S.D.Katz] intermediate range of the QCD phase diagram with high net-baryon densities of strong interest because of expected structures as 1st order phase transition and critical point chiral phase transition deconfinement = chiral phase transition ? hadrons and quarks at high  ? signatures (measurable!) for these structures/ phases? how to characterize the medium?

Claudia Höhne ISHIP 2008, GSI, November What do we know from experiment? → Heavy-ion collisions: chemical freeze-out curve top SPS, RHIC (high T, low  B ): partonic degrees of freedom, crossover (?) RHIC: first steps towards a quantitative characterization of the medium (gluon density, viscosity, energy loss...) lower SPS (intermediate T-  B ): intriguing observations around 30 AGeV! SIS, AGS: high density baryonic matter QCD phase diagram & experiments [Andronic et al. Nucl. Phys. A 772, 167 (2006).

Claudia Höhne ISHIP 2008, GSI, November Within the next years we'll get a complete scan of the QCD phase diagram with 2nd generation experiments LHC, RHIC: bulk observables and rare probes (charm, dileptons) RHIC energy scan: bulk observables √s ~ (5)10 GeV – 200 GeV NA61: focus on fluctuations (√s NN = 4.5 – 17.3 GeV), A < 120 NICA: strangeness, bulk observables (√s NN = 3 – 9 GeV) CBM: bulk observables and rare probes (charm, dileptons) beam energy 10 – 45 GeV/nucleon (√s NN = 4.5 – 9.3 GeV) HADES: bulk observables, dileptons beam energy 2 – 10 GeV/nucleon Experimental scan of QCD phase diagram [Andronic et al. Nucl. Phys. A 772, 167 (2006). HADES CBM, NA61, NICA LHC RHIC FAIR beam intensities: up to 10 9 ions/s

Claudia Höhne ISHIP 2008, GSI, November SPS results [Andronic et al. Nucl. Phys. A 772, 167 (2006).] [NA49, PRC 77, (2008)] energy dedendence of hadron production → changes in SPS energy regime discussions ongoing: hadron gas → partonic phase baryon dominated → meson dominated matter missing: high precision measurements, systematic investigations, correlations, rare probes → quantitative characterization of the medium!

Claudia Höhne ISHIP 2008, GSI, November Statistical Model F. Becattini et al., Phys. Rev. C73 (2006), High net baryon densities at low SPS energies BRAHMS Phys. Rev. Lett. 93 (2004), NA49 (158) Phys. Rev. Lett. 82 (1999), 2471 E802 Phys. Rev. C 60 (1999), NA49 preliminary Central Pb+Pb/Au+Au [NA49, compilation C. Blume] low SPS/ AGS energies: high net- baryon densities at mid-rapidity change to nearly net-baryon free region at RHIC change of shape most pronounced at SPS energies: peak → dip construction of total net-baryon distribution: S x from stat. model fits

Claudia Höhne ISHIP 2008, GSI, November High net-baryon density matter at CBM high baryon and energy densities created in central Au+Au remarkable agreement between different models (not shown) [CBM physics group, C. Fuchs, E. Bratkovskaya priv. com.] beam energy max.  /  0 max  [GeV/fm 3 ] time span ~FWHM 5 AGeV61.5~ 8 fm/c 40 AGeV12> 10~ 3.5 fm/c

Claudia Höhne ISHIP 2008, GSI, November Elliptic flow KE T =m T -m all particles flow (even D-mesons!) scaling if taking the underlying number of quarks into account! → like (all!) quarks flow and combine to hadrons at a later stage (hadronisation) data can only be explained assuming a large, early built up pressure in a nearly ideal liquid (low viscosity!) baryons n=3 mesons n=2 [PHENIX, PRL.98:162301,2007]

Claudia Höhne ISHIP 2008, GSI, November Elliptic flow data at top SPS support hypothesis of early development of collectivity influence of hadronic rescattering phase, resonance decay? lack of complete thermalization, viscosity effect? larger pt-range needed Pb+Pb collisions, √s NN = 17.3 GeV [NA49, G. Stefanek, PoS CPOD2006:030,2006]

Claudia Höhne ISHIP 2008, GSI, November Elliptic flow → stiffness of medium (EOS), pressure collapse of elliptic flow of protons at lower energies signal for first order phase transition?! central midcentral peripheral [NA49, PRC68, (2003)] Elab ~ 30 AGeV [Paech, Reiter, Dumitru, Stoecker, Greiner, NPA 681 (2001) 41] ? particle identified flow data for large pt-range!

Claudia Höhne ISHIP 2008, GSI, November AMPT calculations: C.M. Ko at CPOD 2007 Elliptic flow at FAIR... including charm! probe for dense matter!

Claudia Höhne ISHIP 2008, GSI, November [A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, arXiv: ] Statistical hadronization model (SHM) (c-cbar in partonic phase) O. Linnyk, E.L. Bratkovskaya, W. Cassing, H. Stöcker, Nucl.Phys.A786: ,2007 Hadronic model (HSD) NN → D Λ c N NN → DD NN NN → J/ψ NN Charm production in hadronic and partonic matter

Claudia Höhne ISHIP 2008, GSI, November Charm production in hadronic and partonic matter no charm (J/  ) data below 158 AGeV beam energy detailed information including phase space distributions!

Claudia Höhne ISHIP 2008, GSI, November Critical point critical region might be small focussing effect? fluctuations would need time to develop [Schaefer, Wambach, PRD75, (2007)][Asakawa, Bass, Mueller, Nonaka, PRL 101, (2008)]

Claudia Höhne ISHIP 2008, GSI, November Event-by-event fluctuations [NA49 collaboration, arXiv: v2 [nucl-ex]]arXiv: v2 observation might become enormously difficult correlation length  of sigma field, may become rather small for a finite lifetime of the fireball large acceptance needed! [Stephanov, Rajagopal, Shuryak, PRD60, (1999)] 1st try to identify 1st order phase transition line fluctuations, correlations with large acceptance and particle identification

Claudia Höhne ISHIP 2008, GSI, November CBM: Physics topics and Observables Onset of chiral symmetry restoration at high  B in-medium modifications of hadrons ( , ,   e + e - (μ + μ - ), D) Deconfinement phase transition at high  B excitation function and flow of strangeness (K, , , ,  ) excitation function and flow of charm (J/ψ, ψ', D 0, D ,  c ) charmonium suppression, sequential for J/ψ and ψ' ? The equation-of-state at high  B collective flow of hadrons particle production at threshold energies (open charm) QCD critical endpoint excitation function of event-by-event fluctuations (K/π,...) predictions? clear signatures? → prepare to measure "everything" including rare probes → systematic studies! (pp, pA, AA, energy) aim: probe & characterize the medium! - importance of rare probes!!

Claudia Höhne ISHIP 2008, GSI, November The CBM experiment tracking, momentum determination, vertex reconstruction: radiation hard silicon pixel/strip detectors (STS) in a magnetic dipole field hadron ID: TOF (& RICH) photons,  0,  : ECAL electron ID: RICH & TRD   suppression  10 4 PSD for event characterization high speed DAQ and trigger → rare probes! muon ID: absorber + detector layer sandwich  move out absorbers for hadron runs RICH TRD TOF ECAL magnet absorber + detectors STS + MVD

Claudia Höhne ISHIP 2008, GSI, November STS tracking – heart of CBM Challenge: high track density:  600 charged particles in  25 10MHz Task track reconstruction: 0.1 GeV/c < p  GeV/c  p/p ~ 1% (p=1 GeV/c) primary and secondary vertex reconstruction (resolution  50  m) V 0 track pattern recognition c  = 312  m radiation hard and fast silicon pixel and strip detectors self triggered FEE high speed DAQ and trigger online track reconstruction!

Claudia Höhne ISHIP 2008, GSI, November max: up to ~10 9 tracks/s in the silicon tracker (10 MHz, ~100 tracks/event) start scenario for D more like 0.1 MHz → 10 7 tracks/s → fast track reconstruction! optimize code, port C++ routines to dedicated hardware parallel processing → today: factor speedup of tracking code achieved! long term aim: make use of manycore architectures of new generation graphics cards etc. Track reconstruction GeForce core GPU

Claudia Höhne ISHIP 2008, GSI, November Double and triple GEM detectors 2 Double-sided silicon microstrip detectors Radiation tolerance studies for readout electronics Full readout and analysis chain: Front-end board with self-triggering n-XYTER chip Readout controller Data Acquisition System online offline Go4Go4 Analysis Detector signals Successful test of CBM prototype detector systems with free-streaming read-out electronics using proton beams at GSI, September 28-30, 2008 GSI and AGH Krakow VECC Kolkata KIP Heidelberg

Claudia Höhne ISHIP 2008, GSI, November GSI, Darmstadt, Germany JINR, Dubna, Russia KIP, Heidelberg, Germany VECC, Kolkata, India AGH, Krakow, Poland 90 Sr  - spectra... Detector commissioning:... in several channels of a silicon microstrip detector... and in a GEM detector Operation on the beam line: Participants: Beam spot seen on a GEM detector (every 2 nd channel read out) Correlation of fired channels in two silicon microstrip detectors www-cbm.gsi.de

Claudia Höhne ISHIP 2008, GSI, November CBM hardware R&D RICH mirror n-XYTER FEB Silicon microstrip detector MVD: Cryogenic operation in vacuum RPC R&D Forward Calorimeter GEM dipole magnet

Claudia Höhne ISHIP 2008, GSI, November Monolithic Acitive Pixel Sensors in commercial CMOS process 10  10  m 2 pixels fabricated,  > 99%,  x ~ 1.5 – 2.5  m Micro Vertex Detecor (MVD) Development Artistic view of the MVD mechanical system integration material for cooling! → material budget! vacuum compatibility die thinned to 50  m glued to support. IPHC, Strasbourg (M. Winter et al.)

Claudia Höhne ISHIP 2008, GSI, November D-meson Simulations CbmRoot simulation framework, GEANT3 implemented through VMC full event reconstruction: track reconstruction, particle-ID (RICH, TRD, TOF), 2ndary vertex finder feasibility studies: central Au+Au collisions at 25 AGeV beam energy (UrQMD) several channels studied: D 0, D ±, D s,  c signal multiplicities from HSD, stat model (SM); e.g. HSD = 8.4  10 -5, SM ½ less important layout studies: MAPS position (5cm, 10cm), thickness (150  m – 500  m) D-D- D+D+ MAPS thickness D+ efficiency D+ S/B (2  ) 150  m 4.2%9 500  m 1.05%1.9 D + →  +  + K - (c  = 312  m, BR 9%) D 0 → K -  + (c  = 123  m, BR 3.85%)  c → pK -  + (c  = 60  m, BR 5%)

Claudia Höhne ISHIP 2008, GSI, November CBM feasibility studies feasibility studies performed for all major channels including event reconstruction and semirealistic detector setup D0D0 cc J/   di-electronsdi-muons '' ''

Claudia Höhne ISHIP 2008, GSI, November    b   p p   Signal: strange dibaryon (  0  ) b   (cτ=3cm) M= 10 -6, BR = 5% Background: 25 AGeV 32  per central event 11  reconstructable π K p χ 2 primary > 3(  ) Particle identification with CBM KS0KS0 Λ Be prepared for exotica: multi-strange di-baryons

Claudia Höhne ISHIP 2008, GSI, November Detector layout optimization: RICH first ansatz: gaseous RICH detector (N 2 radiator), ~ 100 m 3 volume, 200k channels for photodetector (photomultiplier, pixel size appr. 6x6 mm 2 ), Be mirrors (glass coating) optimization process: ~40 m 3 volume, CO 2 radiator, 55k channels, glass mirrors RICH + TRD 75% efficiency 10 4  suppression photodetector: H8500 MAPMT, UV glass window 15 – 22 hits/ring

Claudia Höhne ISHIP 2008, GSI, November Detector layout optimization: Muon absorber central Au+Au collisions at 25 AGeV 10 cm Fe 20 cm Fe 30 cm Fe 40 cm Fe hit density after 1st absorber total absorber length 125 cm = 7.5 I

Claudia Höhne ISHIP 2008, GSI, November – high  B, moderate T: searching for the landmarks of the QCD phase diagram first order deconfinement phase transition chiral phase transition QCD critical endpoint → systematic measurements, rare probes characterizing properties of baryon dense matter in medium properties of hadrons? in A+A collisions from AGeV (√s NN = 4.5 – 9.3 GeV) starting in 2016 at SIS 300 Summary – physics of CBM

Claudia Höhne ISHIP 2008, GSI, November CBM + SIS 100 in 2014 Rigidity Bρ = 100 Tm: Au beam 10 AGeV Ni beam 14 AGeV p beam 30 GeV HADES: electrons, hadrons CBM "light" (magnet, Silicon tracker, TOF): p, K, π, Λ, Ξ, Ω,..., flow, fluctuations, up to Au+Au

Claudia Höhne ISHIP 2008, GSI, November SIS 100 A+A collisions at 8 AGeV beam energy, p+A at 30 GeV/c first feasibility studies: charm production for p+C at 30 GeV/c multiplicities from HSD events J/  →  +  - S/B ~150  23 % 4 J/ψ→μ + μ - in 10 9 central events

Claudia Höhne ISHIP 2008, GSI, November CBM collaboration Russia: IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg China: Tsinghua Univ., Beijing CCNU Wuhan USTC Hefei Croatia: University of Split RBI, Zagreb Portugal: LIP Coimbra Romania: NIPNE Bucharest Bucharest University Poland: Krakow Univ. Warsaw Univ. Silesia Univ. Katowice Nucl. Phys. Inst. Krakow LIT, JINR Dubna MEPHI Moscow Obninsk State Univ. PNPI Gatchina SINP, Moscow State Univ. St. Petersburg Polytec. U. Ukraine: INR, Kiev Shevchenko Univ., Kiev Univ. Mannheim Univ. Münster FZ Rossendorf GSI Darmstadt Czech Republic: CAS, Rez Techn. Univ. Prague France: IPHC Strasbourg Germany: Univ. Heidelberg, Phys. Inst. Univ. HD, Kirchhoff Inst. Univ. Frankfurt Hungaria: KFKI Budapest Eötvös Univ. Budapest India: Aligarh Muslim Univ., Aligarh IOP Bhubaneswar Panjab Univ., Chandigarh Gauhati Univ., Guwahati Univ. Rajasthan, Jaipur Univ. Jammu, Jammu IIT Kharagpur SAHA Kolkata Univ Calcutta, Kolkata VECC Kolkata Univ. Kashmir, Srinagar Banaras Hindu Univ., Varanasi Korea: Korea Univ. Seoul Pusan National Univ. Norway: Univ. Bergen Kurchatov Inst. Moscow LHE, JINR Dubna LPP, JINR Dubna Cyprus: Nikosia Univ. 55 institutions, > 400 members Dubna, Oct 2008