# Presentation: 197887

## The Compressed Baryonic Matter  Experiment

- at the Future Accelerator  Facility in Darmstadt

- Outline:
-          Probing dense baryonic matter
-          Experimental observables
-          Technical challenges and (possible) solutions

- Peter Senger

##     The future international accelerator facility 

**SIS 100 Tm**
**SIS 300 Tm**
**U: 35 AGeV **
**p: 90  GeV **

- Structure of Nuclei
-  far from Stability

- Cooled antiproton beam:
- Hadron Spectroscopy

- Compressed Baryonic Matter

-     The future international accelerator facility

- Key features:
- Generation of intense,
- high-quality secondary beams
- of rare isotopes and antiprotons.
- Two  rings: simultaneous beams.

- Ion and Laser Induced Plasmas:
- High Energy Density in Matter

## Mapping the QCD  phase diagram 

- Mapping the QCD  phase diagram
- with heavy-ion collisions

- baryon density:
- B  4 ( mT/2)3/2  x
- [exp((B-m)/T) - exp((-B-m)/T)]
-        baryons      -  antibaryons

- P. Braun-Munzinger

**SIS300**

## Experimental situation : Strangeness enhancement ?

- P. Braun-Munzinger et al.
- Nucl. Phys. A 697 (2002) 902

- Experimental situation : Strangeness production in central Au+Au and  Pb+Pb collisions

- New results from  NA49 (CERN Courier Oct. 2003)

**SIS**
**100**
**300**

**SIS**
**100**
**300**

## 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 ?

## Invariant mass of  electron-positron pairs  from  Pb+Au at 40 AGeV

- Invariant mass of  electron-positron pairs  from  Pb+Au at 40 AGeV

- CERES Collaboration                   S. Damjanovic and K. Filimonov, nucl-ex/0109017

- ≈185 pairs!

## J/ experiments: a count rate estimate

- J/ multiplicity                  1.5·10-5                     1·10-3
- beam intensity                  2·108/s                      2·107/s
- interactions                       8·106/s  (4%)            2·106/s (10%)
- central collisions               8·105/s                      2·105/s
- J/ rate                            12/s                           200/s
- 6% J/e+e- (+-)            0.7/s                           12/s
- spill fraction                      0.8                              0.25
- acceptance                       0.25                             0.1
- J/ measured                    0.14/s                          0.3/s
-                                        8·104/week                   1.8·105/week

- J/ experiments: a count rate estimate

## Charmed mesons

- Some hadronic decay modes
- D (c = 317 m):
- D+  K0+ (2.90.26%)
- D+  K-++  (9  0.6%)
- D0 (c = 124.4 m):
- D0  K-+  (3.9  0.09%)
- D0  K-+ + - (7.6  0.4%)

- D meson production in pN collisions

- Measure displaced vertex
- with resolution of   30 μm !

## The CBM Experiment

-  Radiation hard Silicon pixel/strip detectors in a magnetic dipole field
-  Electron detectors: RICH & TRD & ECAL:  pion suppression up to 105
-  Hadron identification:  RPC, RICH
-  Measurement of photons, π0, η, and muons:  electromagn. calorimeter (ECAL)
-  High speed data acquisition and trigger system

## Experimental challenges

-   107 Au+Au  reactions/sec
-      (beam intensities up to  109 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 -
- 400 +
-   44 K+
-   13 K-

## Design of a Silicon Pixel detector

- MIMOSA IV
- IReS / LEPSI Strasbourg

- Design goals:
-  low materal budget: d < 200 μm
-  single hit resolution < 20 μm
-  radiation hard  (dose 1015 neq/cm2)
-  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

## Experimental conditions 

- Hit rates for 107 minimum bias Au+Au collisions at 25 AGeV:

- Experimental conditions

- Rates of > 10 kHz/cm2 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/cm2
-  Position resolution of about 200 μm
-  Large area ( 500 m2, 9 layers)

- Roadmap:
- Outer part: ALICE TRD
- Inner part:
-  GEM/MICROMEGAS readout chambers
-  Straw tube TRT (ATLAS)
-  Fast read-out electronics

## 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 109 Ohm cm.)
- P. Fonte, Coimbra

## 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

## CBM R&D Collaboration : 38 institutions , 15 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

- _Romania_:
- NIPNE Bucharest
- _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
- PNPI Gatchina
- SINP, Moscow State Univ.
- _Spain:_
- Santiago de Compostela Univ.
- _Ukraine:_
- Univ.  Kiev

- _Hungaria:_
- KFKI Budapest
- Eötvös Univ. Budapest
- _Italy:__ _
- INFN Frascati
- _Korea:_
- Korea Univ. Seoul
- Pusan National Univ.
- _Norway:_
- Univ. Bergen
- _Poland:_
- Jagiel. Univ. Krakow
- Silesia Univ. Katowice
- Warsaw Univ.
- Warsaw Tech. Univ.
- _Portugal_:
- LIP Coimbra