The Compressed Baryonic Matter Experiment at the Future Facility for Antiproton and Ion Research (FAIR) Outline:  Physics: Exploring the QCD phasediagram  Observables  Technical challenges Peter Senger

States of strongly interacting matter baryons hadrons partons Compression + heating = quark-gluon plasma (pion production) Neutron stars Early universe

Exploring the phase diagram of strongly interacting matter CERN-SPS, RHIC, LHC: high temperature, low baryon density GSI SIS300: moderate temperature, high baryon density

The critical end point Mapping the QCD phase diagram with heavy-ion collisions baryon density:  B  4 ( mT/2  h 2 c 2 ) 3/2 x [exp((  B -m)/T) - exp((-  B -m)/T)] baryons - antibaryons Freeze-out points calculated from measured particle ratios using the statistical model Lattice QCD calculations: Fedor & Katz, Ejiri et al.

“Trajectories” (3 fluid hydro) Hadron gas EOS Ivanov & Toneev Calculations reproduce freeze-out conditions 30 AGeV trajectory close to the critical endpoint

 B  3-8  0, T  130 MeV Fundamental questions:  Equation-of-state at high densities: supernova dynamics, stability of neutron stars  In-medium hadron properties: chiral symmetry restoration, origin of hadron masses?  deconfinement

Diagnostic probes

High energy Au+Au collisions in transport calculations B. Friman, W. Nörenberg, V.D. Toneev Eur. Phys. J. A3 (1998) 165

Pion multiplicities per participating nucleons

CBM physics topics and observables 1. In-medium modifications of hadrons  onset of chiral symmetry restoration at high  B measure: , ,   e + e - open charm (D mesons) 2. Strangeness in matter (strange matter?)  enhanced strangeness production ? measure: K, , , ,  3. Indications for deconfinement at high  B  anomalous charmonium suppression ? measure: J/ , D  softening of EOS measure flow excitation function 4. Critical point  event-by-event fluctuations 5. Color superconductivity  precursor effects ?

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

Measure spectral functions of vector mesons via their decay into electron-positron pairs (penetrating probes!) using Ring Imaging Cherenkov detectors CERN-SPS CH 4 radiator gas:  thr = 32 GSI C 4 F 10 radiator gas:  thr = 18.3 UV-det.: fast CsI cathode

Invariant mass of electron-positron pairs from Pb+Au at 40 AGeV CERES Collaboration S. Damjanovic and K. Filimonov, nucl-ex/ ≈185 pairs!

Statistical hadron gas model P. Braun-Munzinger et al. Nucl. Phys. A 697 (2002) 902 Experimental situation : Strangeness enhancement ? Experimental situation : Strangeness production in central Au+Au and Pb+Pb collisions New results from NA49 (CERN Courier Oct. 2003) SIS SIS

Signatures of the quark-pluon plasma ? Enhanced production of strangeness ?? Anomalous suppression of charmonium (J/  ) ??

Probing quark-gluon matter with charmonium NA50 Collaboration at CERN: J/  (cc)   +  - (6%)

Radiation-hard silicon pixel detectors (LHC development) Idea: identify prompt dimuon pairs and those from decaying D-Dbar pairs by precise vertex-determination Upgrade of NA50 at CERN-SPS: indirect measurement of D-mesons 10 planes 88 pixel readout chips channels pixel size : 50  425  m 2

SIS18 SIS100/ 300 Meson production in central Au+Au collisions W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745

The critical point gas liquid coexistence Below T c : 1. order phase transition above T c : no phase boundary At the critical point: Large density fluctuations, critical opalescence Event-by-event analysis by NA49: 5% most central Pb+Pb collisions at 158 AGeV

Fluctuations: Energy scan NA49 nucl-ex/ NA49: dynamical fluctuations increase towards low energies K/  : not reproduced by UrQMD

Observables: p, , K, , , , , , , , D, J /  (3-diff. cross sect., correlations, dileptonic decays, event-by-event observables,... ) exotica: strange clusters, pentaquarks, … The experimental program of CBM: Collision systems: A+A collisions from 8 to 45 (35) AGeV, Z/A=0.5 (0.4) p+A collisions from 8 to 90 GeV p+p collisions from 8 to 90 GeV Beam energies up to 8 AGeV: HADES Accelerator performance: Beam energy sufficient to create high densities High beam intensity and duty cycle, Excellent beam quality, High availability

Experimental challenges  10 7 Au+Au reactions/sec (beam intensities up to 10 9 ions/sec, 1 % interaction target)  determination of (displaced) vertices with high resolution (  30  m)  identification of electrons and hadrons Central Au+Au collision at 25 AGeV: URQMD + GEANT4 160 p 400   + 44 K + 13 K -

The CBM Experiment  Radiation hard Silicon pixel/strip detectors in a magnetic dipole field  Electron detectors: RICH & TRD & ECAL: pion suppression up to 10 5  Hadron identification: RPC, RICH  Measurement of photons, π 0, η, and muons: electromagn. calorimeter (ECAL)  High speed data acquisition and trigger system

Feasibility studies Event generators: URQMD, PLUTO Transport: GEANT3,4 via VMC

y p t [GeV/c]  Kp acceptances

y p t [GeV/c] D0D0 J/ψ acceptances

central collisions 25 AGeV Au+Au 158 AGeV Pb+Pb J/  multiplicity 1.5· ·10 -3 beam intensity 1·10 9 /s 2·10 7 /s interactions 1·10 7 /s (1%) 2·10 6 /s (10%) central collisions 1·10 6 /s 2·10 5 /s J/  rate 15/s 200/s 6% J/  e + e - (  +  - ) 0.9/s 12/s spill fraction acceptance 0.25  0.1 J/  measured 0.17/s  0.3/s  1·10 5 /week  1.8·10 5 /week J/  experiments: a count rate estimate E lab [GeV]

Single electron spectra Feasibility studies: charmonium measurements Assumptions: ideal tracking ideal electron identification, Pion suppression 10 4 Background: URQMD Au+Au 25 AGeV + GEANT4 Electron-positron pair invariant mass Cuts: p t > 1 GeV/c θ > 10 o

Cuts: 1. single electron: - p t > 0.1 GeV/c - d < 50  m 2. electron pair: - v z < 0.1 cm - v t < 0.01 cm - D < 0.01 cm - Θ > 10° S/B = 0.3 (ρ+  ) S/B = 1.2 (  ) Low mass electron-positron pairs Assumptions: ideal tracking and electron identification Background: URQMD Au+Au 25 AGeV + GEANT4

Charmed mesons Some hadronic decay modes D  (c  = 317  m): D +  K 0  + (2.9  0.26%) D +  K -  +  + (9  0.6%) D 0 (c  =  m): D 0  K -  + (3.9  0.09%) D 0  K -  +  +  - (7.6  0.4%) D meson production in pN collisions Measure displaced vertex with resolution of  30 μm !

Feasibility study : open charm Background suppression by cut on detached vertex :  1000 D 0  K -  + (central 25 AGeV) Assuming = : S/B  1 Crucial detector parameters: Material budget of first 2 Silicon stations Single hit resolution Similar studies: D +  K -  +  +, D *± → D 0  ±

MIMOSA IV IReS / LEPSI Strasbourg Design of a Silicon Pixel detector Design goals: low materal budget: d < 200 μm single hit resolution < 20 μm radiation hard (dose neq/cm 2 ) fast read out Silicon Tracking System: 7 planar layers of pixels/strips. Vertex tracking by two first pixel layers at 5 cm and 10 cm downstream target Roadmap: R&D on Monolithic Active Pixel Sensors (MAPS) pitch 20 μm thickness below 100 μm single hit resolution :  3 μm Problem: radiation hardness and readout speed Fallback solution: Hybrid detectors

Design of a fast RICH Design goals: electron ID for γ > 42 e/π discrimination > 100 hadron blind up to about 6 GeV/c low mass mirrors (Be-glass) fast UV detector URQMD + GEANT4: Au+Au 25 AGeV radiator (40% He + 60% CH 4 )  40 rings per event, photons per ring (incl. efficiencies)

Pion misidentification a)0%b)0.01% c)0.1%d)1%

pions from Au+Au 25 AGeV Cherenkov threshold electrons producing Cherenkov light Au+Au 25 AGeV 100 events URQMD+GEANT4 pion threshold 5.9 GeV/c 90% saturation angle at 13.5 GeV/c Pion suppression with RICH

Hit rates for 10 7 minimum bias Au+Au collisions at 25 AGeV: Experimental conditions Rates of > 10 kHz/cm 2 in large part of detectors !  main thrust of our detector design studies

Hadron identification σ TOF = 80 ps Bulk of kaons (protons) can well be identified with σ TOF = 80 – 100 ps

Design of a high rate RPC Design goals: Time resolution ≤ 80 ps High rate capability up to 25 kHz/cm2 Efficiency > 95 % Large area  150 m2 Long term stability Prototype test: detector with plastic electrodes (resistivity 10 9 Ohm cm.) P. Fonte, Coimbra

DAQ / Trigger Architecture clock Practically unlimited size Max. latency uncritical Avr. latency relevant Detector Front end ADC Buffer memory Event builder and selector Self triggered digitization: Dead time free Each hit transported as Address/Timestap/Value Compensates builder/selector latency Use time correlation of hits to define events. Select and archive. Challenge : reconstruct 1.5 x 10 9 track/sec. data volume in 1 st level trigger  50 Gbytes/sec. archiving rate 1 Gbyte/sec (event size 40 kbyte, event rate 25 kHz)

CBM Collaboration : 39 institutions, 14 countries Croatia: RBI, Zagreb Cyprus: Nikosia Univ. Czech Republic: Czech Acad. Science, Rez Techn. Univ. Prague France: IReS Strasbourg Germany: Univ. Heidelberg, Phys. Inst. Univ. HD, Kirchhoff Inst. Univ. Frankfurt Univ. Mannheim Univ. Marburg Univ. Münster FZ Rossendorf GSI Darmstadt Russia: CKBM, St. Petersburg IHEP Protvino INR Troitzk ITEP Moscow KRI, St. Petersburg Kurchatov Inst., Moscow LHE, JINR Dubna LPP, JINR Dubna LIT, JINR Dubna Obninsk State Univ. PNPI Gatchina SINP, Moscow State Univ. St. Petersburg Polytec. U. Spain: Santiago de Compostela Univ. Ukraine: Shevshenko Univ., Kiev Univ. of Kharkov Hungaria: KFKI Budapest Eötvös Univ. Budapest Korea: Korea Univ. Seoul Pusan National Univ. Norway: Univ. Bergen Poland: Krakow Univ. Warsaw Univ. Silesia Univ. Katowice Portugal: LIP Coimbra Romania: NIPNE Bucharest

CBM R&D working packages Feasibility, Simulations D  Kπ(π) GSI Darmstadt, Czech Acad. Sci., Rez Techn. Univ. Prague ,ω,   e + e - Univ. Krakow JINR-LHE Dubna J/ψ  e + e - INR Moscow Hadron ID Heidelberg Univ, Warsaw Univ. Kiev Univ. NIPNE Bucharest INR Moscow GEANT4: GSI Tracking KIP Univ. Heidelberg Univ. Mannheim JINR-LHE Dubna Design & construction of detectors Silicon Pixel IReS Strasbourg Frankfurt Univ., GSI Darmstadt, RBI Zagreb, Univ. Krakow Silicon Strip SINP Moscow State U. CKBM St. Petersburg KRI St. Petersburg RPC-TOF LIP Coimbra, Univ. Santiago de Com., Univ. Heidelberg, GSI Darmstadt, Warsaw Univ. NIPNE Bucharest INR Moscow FZ Rossendorf IHEP Protvino ITEP Moscow Fast TRD JINR-LHE, Dubna GSI Darmstadt, Univ. Münster INFN Frascati Straw tubes JINR-LPP, Dubna FZ Rossendorf FZ Jülich Tech. Univ. Warsaw ECAL ITEP Moscow GSI Darmstadt Univ. Krakow RICH IHEP Protvino GSI Darmstadt Trigger, DAQ KIP Univ. Heidelberg Univ. Mannheim GSI Darmstadt JINR-LIT, Dubna Univ. Bergen KFKI Budapest Silesia Univ. Katowice Univ. Warsaw Magnet JINR-LHE, Dubna GSI Darmstadt Analysis GSI Darmstadt, Heidelberg Univ, Data Acquis., Analysis

FAIR cost (M€) Total: 675 Buildings: SIS100: 70.1 SIS200: 39.6 Coll. Ring: 45.0 NESR: 40.0 HESR: 45.0 e-ring: 15.0 Beamlines: 21.0 Cryo, etc: 44.1 SFRS: 40.7 CBM: 27.0 AP: 8.7 Plasma phys.: 8.0 p-linac: 10.0 PANDA: 28.4 pbar targ.: 6.9 FAIR milestones Oct : Submission of the Conceptual Design Report Nov. 2002: Positive evaluation report of the German science council Feb. 2003: Project approved by the German federal government (170 M€ foreign contributions requested) Jan. 2004: Letters of intent submitted Feb. 2004: 1. Meeting of Internat. Steering Committee (12 nations) June 2004: Evaluation of the LOI,s by PACs Jan 2005: Submission of Technical Reports

SIS18 Upgrade 70 MW Connection Proton-Linac TDM # SIS100 Transfer Line SIS18-SIS100 High Energy Beam Lines RIB Prod.-Target, Super-FRS RIB High+Low Energy Branch Antiproton Prod.-Target CR-Complex HESR & 4 MV e - –Cooling NESR SIS200* 8 MV e - –Cooling e-A Collider SIS100/200 Tunnel, SIS Injection+Extraction+Transfer Transfer Buildings/Line Super-FRS, Auxiliary Bldgs., Transfer Tunnel to SIS18, Building APT, Super-FRS, CR-Complex RIB High+Low Energy Branch, HESR ( ground level), NESR, AP-cave, e-A Collider, PP-cave CBM-Cave, Pbar-Cave, Reinjection SIS100 Civil Construction Civil Construction 1 Civil Construction 3 Civil Construction 2 Civil Construction 4 I IV III V II Concept for staged Construction of FAIR 2,7x10 11 /s 238 U 28+ (200 MeV/u) 5x10 12 protons per puls 1x10 11 /s 238 U 28+ ( GeV/u) ->RIB (50% duty cycle) 2.5x10 13 p (1-30 GeV) 3-30 GeV pbar->fixed target 10.7 GeV/u 238 U -> HADES* 1x10 12 /s 238 U % duty cycle pbar cooled p (1-90 GeV) 35 GeV/u 238 U 92+ NESR physics plasma physics Experiment Potential # Construction Tunnel Drilling Machine General Planning Civil ConstructionProduction and Installation *SIS200 installation during SIS100 shut down

Mapping the QCD phase diagram with heavy-ion collisions  B  6  0  B  0.3  0 baryon density:  B  4 ( mT/2  ) 3/2 x [exp((  B -m)/T) - exp((-  B -m)/T)] baryons - antibaryons P. Braun-Munzinger SIS300 C. R. Allton et al, hep-lat Lattice QCD : maximal baryon number density fluctuations at T C for  q = T C (  B  500 MeV)

Design of a fast TRD Design goals: e/π discrimination of > 100 (p > 1 GeV/c) High rate capability up to 150 kHz/cm 2 Position resolution of about 200 μm Large area (  500 m 2, 9 layers) Roadmap: Outer part: ALICE TRD Inner part: GEM/MICROMEGAS readout chambers Straw tube TRT (ATLAS) Fast read-out electronics

EU FP6 Hadron Physics (2004 – 2006) Joint Research Projects (approved): Fast gaseous detectors Partner: INVENTOR, Krakow Advanced TOF Systems Future DAQ and trigger systems (Silesia Univ. Katowice, Univ. Warszawa) Network activities (approved): CBMnet (Silesia Univ. Katowice, Univ. Krakow, Univ. Warszawa) CBM Participation in EU Programmes: INTAS-GSI ( ) approved projects: Transition Radiation Detectors Straw tube tracker (Univ. Tech. Warszawa) Resistive Plate Chambers Electromagnetic calorimeter (Univ. Krakow) New call EU FP6 (opened Nov.03, closed Mar04): Design of new facilities Construction of new facilities

Mapping the QCD phase diagram with heavy-ion collisions  B  6  0  B  0.3  0 Net baryon density:  B  4 ( mT/2  ) 3/2 x [exp((  B -m)/T) - exp((-  B -m)/T)] baryons - antibaryons P. Braun-Munzinger SIS300

Fluctuations: Energy scan dynamical fuctuations reported by NA49 increase towards low energies K/  : not reproduced by UrQMD p/  : correlation due to resonance decays NA49, nucl-ex/ NA49 nucl-ex/