CBM at FAIR Outline:  CBM Physics  Feasibility studies  Detector R&D  Planning, costs, manpower,...

The critical end point Ejiri et al. Fodor-Katz Cross over 1st order transition Mapping the QCD phase diagram with heavy-ion collisions CBM physics: exploring the high density region of the QCD phase diagram. Search for restoration of chiral symmetry partonic matter at large μ B critical endpoint Dense baryon- dominated matter Meson- dominated matter

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

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 ?

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

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

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

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 under way for D +  K -  +  +, D *± → D 0  ±

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

y p t [GeV/c]  Kp acceptances

y p t [GeV/c] D0D0 J/ψ acceptances

event-by event fluctuations: K/  ratio accepted “true” identified (60ps, 70% purity) 10k UrQMD events

Measurement of dynamical fluctuations purity,%  dyn, % 404.0± ± ± ± ± ± ± ±5.2 True value : 5 % 10 % Simulations in progress to improve statistics 10 % fluctuation

Tracking with Silicon Stations Au+Au 25 AGeV: Reconstructed tracks Reconstruction efficiency > 95 % Momentum resolution ≈ 0.6 %

LOI (Jan. 2004): URQMD (and PLUTO) and GEANT4 (no tracking, ideal particle identification, efficiencies 100%,...) CBM software week May 2004 (  50 participants): simulation and analysis framework using VMC (GEANT3/4) based on ROOT Meeting of tracking group in July/August 2004: implementation of tracking algorithms and simple detector reponses (digitizers) Collaboration Meeting Oct. 6-8, 2004: first results of simulations with tracking, particle ID and efficiencies Technical Report Jan. 2005: results of realistic simulations Roadmap for feasibility studies towards the Technical Report

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 n eq/cm 2 ) fast read out (20 – 40 MHz) 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 radiation hard up to n eq/cm 2 read out 0.2 MHz R&D on radiation hardness and read out 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)

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

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: MWPC/GEM/micromegas Straw tube TRT (ATLAS) Fast read-out electronics Simulation of pion suppression: TRD with fast gaseous detector Tests of prototypes (MWPC, GEMs, micromegas): July 2004 at SIS

Design of a high rate RPC Design goals: Time resolution ≤ 80 ps High rate capability up to 25 kHz/cm 2 Efficiency > 95 % Large area  150 m 2 Long term stability Prototype test: detector with plastic electrodes (resistivity 10 9 Ohm cm.) P. Fonte, Coimbra Tests of prototypes with low resistivity glass electrodes: ITEP July 2004

Anode 3 mm pitch Capacitor Block FOPI-Segmented-Anode-RPCs

Granularity: inner region 2x2 cm 2 intermediate region 5x5 cm 2 outer region 10x10 cm 2 Lead-scintillator calorimeter: 0.5 – 1 mm thick tiles 25 X 0 total length PM read out Distance between electron and closest track in the innermost region Design of an electromagnetic calorimeter Tests of detector module prototype: July 2004 at CERN

Run time estimate J/ψ beam energy AGeV J/  mult. produced min. bias J/  yield detected per week runtime weeks 104· · · · · · · · · · · · BR = 6%, ε = 0.1 reaction rate 5 MHz, trigger reduction 10 5 (e - from γ-conversion with p T  1 GeV/c) Additional measurement of excitation functions for: A + A (A= 12, 100) up to 45 AGeV ( 1 year) p + A (A = 12, 100, 200) up to 90 GeV (1 year) p + p up to 90 GeV (6 month) Au + Au  1 year  3.5 years beam on target for J/ψ

Multiplicity: 2x10 -4 / minimum bias event Au+Au 25 AGeV BR = 4%, ε = 0.1, → 8x10 -7 / event Goal: trigger reduction 400 (displaced vertex) reaction rate 10 MHz, trigger rate 25 kHz Number of detected D 0 -Mesons: 8/s (7x10 5 /day) run parallel to charmonium Run time estimate D 0 -Mesons

Run time low-mass vector mesons 4 rho mesons / minimum bias event Au+Au 25 AGeV BR = 4.5x10 -5, ε = 0.1, → 1.8x10 -5 / event Reaction rate without trigger reduction 25 kHz Number of detected rho mesons: 4x10 4 /day Measurements of excitation functions (beam on target) A + A (A= 12, 100, 200) up to 45 AGeV ( 36 weeks) p + A (A = 12, 100, 200) up to 90 GeV (15 weeks) p + p up to 90 GeV (5 weeks)  1 year beam on target

ComponentMio. € TRD (full cost)12 Electromagnetic Calorimeter8 offline computing3 Sum23 CDR: DetectorMio. € Silicon pixel1 Silicon Strip7 RICH3 TRD3 RPC4 Trigger/DAQ3 Super-conducting dipole2 Infrastructure4 Sum27 Cost estimate LOI:

EU FP6 Hadron Physics (2004 – 2006) Joint Research Projects (approved): Fast gaseous detectors Advanced TOF Systems Future DAQ and trigger systems Network activities (approved): CBMnet CBM Participation in EU Programmes: INTAS-GSI ( ) approved projects: Transition Radiation Detectors JINR LHE Dubna, NC PHEP Minsk, INFN Frascati, GSI Darmstadt Straw tube tracker: JINR LPP Dubna, LPI Moscow, PNPI Gatchina, TU Warsaw, FZ Rossendorf, FZ Jülich Resistive Plate Chambers INR Troitzk, IHEP Protvino, ITEP Moscow, LIP Coimbra, Univ. Heidelberg Electromagnetic calorimeter ITEP Moscow, Polimersintez Wladimir, Univ. Krakow, GSI Darmstadt INTAS open call ( ) CBM Network

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 Tools: 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 Pusan Univ. 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

TaskParticipating InstitutionsFTE D-MesonsGSI, CAS Rez, TU Prague1 low-mass vector mesonsU Krakow, JINR-LHE3 charmonium ID via e+e-INR Moscow1 charmonium ID via μ+μ-PNPI, GSI1 hadron ID via TOFHeidelberg, Kiev, NIPNE, INR, RBI3 Hyperon IDPNPI, TU St. Pb1 Sim. & analysis frameworkGSI Darmstadt2 TrackingKIP HD, U Mannheim, JINR-LHE, JINR-LIT5 R&D on Silicon Pixel DetectorIReS, U Frankfurt, GSI, RBI, U Krakow3 R&D on Silicon Strip DetectorMoscow SU, CKBM, KRI, Obninsk Univ2 R&D on RPC TOF detector system with read-out electronics LIP Coimbra, Univ. Santiago, U Heidelberg, GSI, NIPNE, INR, FZR, IHEP, ITEP, Korea Univ., RBI, U Krakow, U Marburg 8 R&D on TRDJINR-LHE, GSI, Univ. Münster, PNPI, NIPNE6 R&D on straw tube trackerJINR-LPP Dubna, FZR Rossendorf2 R&D on RICHIHEP, GSI, Pusan Univ., PNPI4 R&D on ECALITEP, Univ. Krakow,2 Trigger and Data AcquisitionKIP HD, U Mannheim, JINR LIT, GSI, U Bergen, KFKI Budapest, Silesia Univ., PNPI, U Warsaw 7 Superconducting dipole magnetJINR-LHE Dubna, GSI Darmstadt2 SUM53

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

Time schedule Milestones: 1. Technical Proposal begin of Technical Design Report end of 2007 Subproject Si-Tracker RICH TRD TOF-RPC ECAL Trigger/DAQ Electronics Magnet Infrastructure simulations, R&D, designPrototypingConstructionInstallation, test