Folie 1

1
Nucleus-nucleus collisions at the future facility
in Darmstadt - Compressed Baryonic Matter at GSI
Peter Senger

• Outline
• A future accelerator for intense beams
• of (rare) ions and antiprotons
• The CBM experiment
• ? Exploring dense baryonic matter
• ? Observables
• ?Technical challenges and solutions

2
The future international accelerator facility
Key features Generation of intense,
high-quality secondary beams of rare isotopes
and antiprotons. Two rings simultaneous beams.
SIS 100 Tm SIS 300 Tm U 35 AGeV p 90 GeV
Cooled antiproton beam Hadron Spectroscopy
Ion and Laser Induced Plasmas High Energy
Density in Matter
Structure of Nuclei far from Stability
Compressed Baryonic Matter
3
The phase diagram of strongly interacting matter
CERN-SPS, RHIC, LHC high temperature, low
baryon density AGS, GSI (SIS200) moderate
temperature, high baryon density
4
Probing the Chiral phase transition
5
The production of dense and/or hot hadronic matter
Compression heating
quark-gluon
(pion production) matter
early universe
neutron stars
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
High energy AuAu collisions in transport
calculations
B. Friman, W. Nörenberg, V.D. Toneev Eur. Phys.
J. A3 (1998) 165
10
Pion multiplicities per participating nucleons
11
Mapping the QCD phase diagram with heavy-ion
collisions
P. Braun-Munzinger
Analysis of particle ratios with statistical
model chemical freeze-out
baryon density ?B ? 4 ( mT/2?)3/2 x
exp((?B-m)/T) - exp((-?B-m)/T) baryons
- antibaryons
12
CBM physics topics and observables
1. In-medium modifications of hadrons
? onset of chiral symmetry restoration at high
?B measure ?, ?, ? ? ee-
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 at TgtTc ?
Note In heavy ion collisions (?, ?, ? ) ?
ee- not measured from 2 40 AGeV J/? not
measured below 158 AGeV D mesons not measured
at all
13
Looking into the fireball
using penetrating probes short-lived vector
mesons decaying into electron-positron pairs
14
Invariant mass of electron-positron pairs from
PbAu at 40 AGeV
CERES Collaboration S.
Damjanovic and K. Filimonov, nucl-ex/0109017
185 pairs!
15
Signatures of the quark-pluon plasma ?
16
Experimental situation Strangeness production
in central AuAu and PbPb collisions
Experimental situation Strangeness enhancement ?
New results from NA49
Statistical hadron gas model P. Braun-Munzinger
et al. Nucl. Phys. A 697 (2002) 902
17
Comparison of experimental data to results of
transport codes
E.L. Bratkovskaya, W. Cassing, M. van Leeuwen, S.
Soff, H. Stöcker, nucl-th/0307098
18
Probing quark-gluon matter with charmonium
M. C. Abreu and the NA50 Collaboration, Phys.
Lett. B 477 (2000) 28
Interpretation Anomalous J/? suppression in
central PbPb collisions caused by color
screening of cc mesons in quark-gluon matter
NA50 Collaboration at CERN J/? (cc) ?
??- (6)
19
Probing the high density fireball with charm
production
W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl.
Phys. A 691 (2001) 745
20
J/? experiments a count rate estimate
25 AGeV AuAu
158 AGeV PbPb J/?? multiplicity in central
collisions 1.510-5
110-3 beam intensity 2108/s
2107/s interactions
8106/s (4) 2106/s (10) central
collisions 8105/s
2105/s J/? rate 12/s
200/s 6 J/???ee- (??-)
0.7/s 12/s spill
fraction 0.8
0.25 acceptance 0.25
? 0.1 J/? measured
0.14/s ? 0.3/s
? 8104/week ?
1.8105/week
21
Hadrons in the nuclear medium
22
Meson production in central AuAu collisions
W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl.
Phys. A 691 (2001) 745
SIS18 strangeness production at threshold ?
probing in-medium properties at ? 1 -3 ?0
SIS300 charm production near threshold ?
probing in-medium properties at ? 5 -10 ?0
23
Charmed mesons
D meson production in pN collisions
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)
experimental challenges low production cross
section large combinatorial background measure
displaced vertex with resolution of ? 30?m
24
The critical point
Purely statistical fluctuations !
25
Our approach towards the study of superdense
baryonic matter
Produce high baryon densities in heavy ion
collisions at 4 40 AGeV. Build an universal
experiment which measures simultaneously both
hadrons and electrons ?, K, ?, ?, ?, p, ?, ?,
?, ?, D, J/? (multiplicities, phase-space
distributions, centrality, reaction
plane). Perform systematic measurements using a
dedicated accelerator High beam intensity and
duty cycle, Excellent beam quality, High
availability
26
AuAu _at_ 25 AGeV central collision
URQMD event, GEANT simulation B 1 T 160 p
400 ?- 400 ? 44 K 13 K-
?-
p
?
27
Experimental challenges

• ? beam intensities up to 109 ions/sec, 1
  interaction target
• 107 AuAu reactions/sec
• (1000 charged particles in central AuAu
  collisions at 25 AGeV)
• ? determination of (displaced) vertices with high
  resolution (? 30 ?m)
• ? identification of electrons and hadrons

Experimental concept
? Radiation hard Silicon pixel/strip detectors
in a magnetic dipole field ? 2 electron
detectors pion suppression by 104- 105 ?
Particle identification TOF, RICH ?
Electromagnetic calorimeter ? High speed data
acquisition and trigger system
Silicon 7 planes, 3 Mio pixel, 1.5 Mio strips
28
The CBM Experiment
Silicon tracker in B field tracking,
momentum RICH1 ( ? ? 30) electrons
RICH2 high-momentum pions (? 3-4 GeV/c) TRDs
tracking, electrons (? ? 2000) RPC
particle identification via TOF, kaon-pion
separation up to 3-4 GeV/c ECAL electrons,
gammas, ?0,?0
29
(No Transcript)
30
Central AuAu collision at 25 AGeV URQMD
GEANT4 160 p 400 ?- 400 ? 44 K
13 K-
31
CBM RD Collaboration 35 institutions
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. 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 SINP, Moscow State Univ. Spain Santiago
de Compostela Univ.   Ukraine Shevshenko
Univ. , Kiev USA LBNL Berkeley
Hungaria KFKI Budapest Eötvös Univ.
Budapest Italy INFN Catania INFN Frascati
Korea Korea Univ. Seoul Pusan
Univ. Poland Krakow Univ. Warsaw Univ. Silesia
Univ. Katowice   Portugal LIP Coimbra Romania
NIPNE Bucharest
32
RD working packages
Feasibility, Simulations
Design construction of detectors
Data Acquis., Analysis
GEANT4 GSI
Silicon Pixel IReS Strasbourg Frankfurt
Univ., GSI Darmstadt, RBI Zagreb, Krakow Univ.
LBNL Berkeley
Fast TRD JINR-LHE, Dubna GSI Darmstadt, Univ.
Münster INFN Frascati
Trigger, DAQ KIP Univ. Heidelberg Univ.
Mannheim GSI Darmstadt KFKI Budapest Silesia Univ.
?,?, ? ?ee- Univ. Krakow JINR-LHE Dubna
D ? Kp(p) GSI Darmstadt, Czech Acad. Sci.,
Rez Techn. Univ. Prague
Straw tubes JINR-LPP, Dubna FZ Rossendorf FZ
Jülich
Silicon Strip SINP Moscow State U. CKBM St.
Petersburg KRI St. Petersburg
Analysis GSI Darmstadt, Heidelberg Univ,
J/? ? ee- INR Moscow
ECAL ITEP Moscow
RPC-TOF LIP Coimbra, Univ. S. de
Compostela, Univ. Heidelberg, GSI
Darmstadt, NIPNE Bucharest INR Moscow FZ
Rossendorf IHEP Protvino ITEP Moscow
Hadron ID Heidelberg Univ, Warsaw Univ. Kiev
Univ. NIPNE Bucharest INR Moscow
RICH IHEP Protvino
Magnet JINR-LHE, Dubna GSI Darmstadt
Tracking KIP Univ. Heidelberg Univ.
Mannheim JINR-LHE Dubna
33
Project evolution
Project cost (M)
Oct. 2000 1. International Workshop
on a future accelerator
facility Oct. 2001
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) Oct. 2003 2. International
Workshop on the future
accelerator
facility Spring 2004 Letters of intent In
2004 New GSI structure
Total 675 Buildings
225.5 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
34
Concept for staged Construction of the
International Facility for Beams of Ions and
Antiprotons
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

SIS18 Upgrade

70 MW Connection
Proton-Linac TDM

General Planning
2,7x1011 /s 238U28 (200 MeV/u) 5x1012 protons
per puls
I
Civil Construction 1
SIS100/200 Tunnel, SIS InjectionExtractionTransf
er
SIS100 Transfer Line SIS18-SIS100 High Energy
Beam Lines
Transfer Buildings/Line Super-FRS, Auxiliary
Bldgs., Transfer Tunnel to SIS18, Building APT,
Super-FRS, CR-Complex RIB HighLow Energy Branch,
II
Civil Construction 2
RIB Prod.-Target, Super-FRS RIB HighLow Energy
Branch Antiproton Prod.-Target CR-Complex
1x1011/s 238U28 (0.4-2.7GeV/u) -gtRIB (50 duty
cycle) 2.5x1013 p (1-30 GeV) 3-30 GeV pbar-gtfixed
target 10.7 GeV/u 238U -gt HADES
III
Civil Construction 3
CBM-Cave, Pbar-Cave, Reinjection SIS100
HESR 4 MV e- Cooling NESR
IV
HESR ( ground level), NESR, AP-cave, e-A
Collider, PP-cave
Civil Construction 4
SIS200 8 MV e- Cooling e-A Collider
1x1012/s 238U28 100 duty cycle pbar cooled p
(1-90 GeV) 35 GeV/u 238U92 NESR physics plasma
physics
V
Construction Tunnel Drilling Machine
Civil Construction


Experiment Potential
Civil Construction
Production and Installation
SIS200 installation during SIS100 shut down
35
(No Transcript)
36
(No Transcript)
37

• Kopenhagen 2003
• Titel 1 min
• Anlage 2
• phasediagram 1
• Hot dense matter 2
• qq condensate 1
• Filme 2
• Pionen Excitation 1
• Transport 1
• Phasendiagramm 2
• Observable 2
• Dilepton Sonde 0.5
• CERES Daten 1
• QGP 0.5
• NA49 1
• Transport 1
• cc production 1 20 min
• J/psi Vergleich 1

38
International Accelerator Facility for beams of
Ions and Antiprotons
39
Upgrade of NA50 at CERN-SPS indirect measurement
of D-mesons
Idea identify prompt dimuon pairs and those from
decaying D-Dbar pairs by precise
vertex-determination

• 10 planes
• 88 pixel readout chips
• 720 000 channels
• pixel size 50?425 mm2

Radiation-hard silicon pixel detectors (LHC
development)
40
The nuclear reaction experiment at the future
facility at GSI
CBM
HADES
AA at 8-40 AGeV
AA at 2-8 AGeV
41
The nuclear reaction experiment at the future
facility at GSI
ECAL
CBM
42
AuAu _at_ 25 AGeV central collision
URQMD event, GEANT simulation B 1 T 160 p
400 ?- 400 ? 44 K 13 K-
?-
p
?
43
Acceptance
AuAu 25 AGeV URQMD event, GEANT simulation
44
e, e- opening angle
e, e- transverse momentum
cut pT? 1 GeV/c
cut ? ? 10o
45
AuAu 25 AGeV ee- invariant mass spectra
PLUTO simulations 10 Mio. events
signal/background ? 10
46
Simulations on open charm detection
D0??K- performed by V. Friese (GSI)

• Assumptions
• AuAu at 25 AGeV (ltmgt 328 ?, 13 K-)
• Perfect track finding
• Perfect particle identification
• No magnetic field
• Silicon detector thickness 100 ?m
• Tools
• URQMD event generator
• GEANT4 transport code
• ROOT data analysis

47
Identification of D-mesons (open charm) Example
D0 ? K-?

• Suppression of combinatorial background by the
  following cuts
• invariant mass window mD 1864 ? 25 MeV
• displaced decay vertex vz gt 0
• back to back emission in c.m. system (? 180o)
  
• impactparameter bpair b? bK
• colinearity of D and decay products (momentum
  vectors)

48
Displaced decay vertex D0 ? K-?
signal
background
Vertex resolution ??vz 19 ?m Cut vz gt 0,3
mm Cut-efficiency Signal 58.0 background
2.7 x 10-4
S/B
49
Impact parameters of K- and ? at z0
signal
bpair bK x b? Cut bpair lt -0,004
mm2 Cut-efficiency Signal 90.3
background 23.7
background
50
Colinearity (pointing angle)
signal
Cut ?p lt 5º Cut-efficiency Signal 99.9
Background 12.5
background
51
Efficiencies, sensitivity and rates
Total efficiency Signal 48.4 background
5 x 10-6
For ltD0gt 10-3 (HSD-Model) und ?m 10 MeV
3?-limit reached at 1,6 x 106 events Signal/Backgr
ound 1.8
At a reaction rate of 1 MHz (AuAu central
collisions) D0 detection rate (incl. branching
ratio) 13.000 / h