nucleus-nucleus collisions at the future facility in darmstadt - compressed baryonic matter at gsi...
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Nucleus-nucleus collisions at the future facility in Darmstadt -
Compressed Baryonic Matter at GSI
Outline:
A future accelerator for intense beams of (rare) ions and antiprotons The CBM experiment: Exploring dense baryonic matter Observables Technical challenges and solutions
Peter Senger
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
The phase diagram of strongly interacting matter
CERN-SPS, RHIC, LHC: high temperature, low baryon density
AGS, GSI (SIS200): moderate temperature, high baryon density
Probing the Chiral phase transition
B 3-80 , T 130 MeV
Restoration of (spontaneously broken) chiral symmetry
Origin of hadron masses ?
The production of dense and/or hot hadronic matter
Compression + heating = quark-gluon (pion production) matter
neutron stars early universe
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
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
Analysis of particle ratios with statistical model: chemical freeze-out
P. Braun-Munzinger
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 at T>Tc ?
Note: In heavy ion collisions
(, , ) e+e- not measured from 2 – 40 AGeV
J/ not measured below 158 AGeV
D mesons not measured at all
pn
++
K
e+
e-
p
Looking into the fireball …
… using penetrating probes:
short-lived vector mesons decaying into electron-positron pairs
Invariant mass of electron-positron pairs from Pb+Au at 40 AGeVCERES Collaboration S. Damjanovic and K. Filimonov, nucl-ex/0109017
≈185 pairs!
Signatures of the quark-pluon plasma ?
Enhanced production of strangenessAnomalous suppression of charmonium (J/)
Statistical hadron gas modelP. 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
Comparison of experimental data to results of transport codes E.L. Bratkovskaya, W. Cassing, M. van Leeuwen, S. Soff, H. Stöcker, nucl-th/0307098
“Flow generated by extra pressure generated by partonic interactions in the early phase of a central Au+Au/Pb+Pb collision”
Probing the high density fireball with charm production
W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745
25 AGeV Au+Au 158 AGeV Pb+Pb J/ multiplicityin central collisions 1.5·10-5 1·10-3 beam intensity 2·108/s 2·107/sinteractions 8·106/s (4%) 2·106/s (10%)central collisions 8·105/s 2·105/sJ/ rate 12/s 200/s 6% J/e+e- (+-) 0.7/s 12/sspill fraction 0.8 0.25 acceptance 0.25 0.1J/ measured 0.14/s 0.3/s 8·104/week 1.8·105/week
J/ experiments: a count rate estimate10 50 120 210 Elab [GeV]
Hadrons in the nuclear medium
SIS18 SIS300
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
Meson production in central Au+Au collisionsW. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745
Charmed mesons
Some hadronic decay modes
D (c = 317 m):D+ K0+ (2.90.26%)
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 sectionlarge combinatorial backgroundmeasure displaced vertex with resolution of 30m
D meson production in pN collisions
The critical point
gasliquid
coexistence
Below Tc: 1. order phase transitionabove Tc: 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
Purely statistical fluctuations !
Produce high baryon densitiesin 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
Our approach towards the study of superdense baryonic matter
Experimental challenges
beam intensities up to 109 ions/sec, 1 % interaction target: 107 Au+Au reactions/sec (1000 charged particles in central Au+Au collisions at 25 AGeV) determination of (displaced) vertices with high resolution ( 30 m)
identification of electrons and hadrons
Silicon: 7 planes, 3 Mio pixel, 1.5 Mio strips
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 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
The CBM Experiment
Central Au+Au collision at 25 AGeV:URQMD + GEANT4
160 p 400 -
400 + 44 K+ 13 K-
CBM R&D Collaboration : 35 institutions Croatia: RBI, Zagreb
Cyprus: Nikosia Univ. Czech Republic:Czech Acad. Science, RezTechn. Univ. Prague France: IReS Strasbourg
Germany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. FrankfurtUniv. Mannheim Univ. MünsterFZ RossendorfGSI Darmstadt
Russia:CKBM, St. PetersburgIHEP ProtvinoINR TroitzkITEP MoscowKRI, St. PetersburgKurchatov Inst., MoscowLHE, JINR DubnaLPP, JINR DubnaSINP, Moscow State Univ.
Spain: Santiago de Compostela Univ. Ukraine: Shevshenko Univ. , Kiev
USA: LBNL Berkeley
Hungaria:KFKI BudapestEötvös Univ. Budapest
Italy: INFN CataniaINFN Frascati
Korea:Korea Univ. SeoulPusan Univ.
Poland:Krakow Univ.Warsaw Univ.Silesia Univ. Katowice Portugal: LIP Coimbra
Romania: NIPNE Bucharest
R&D working packages Feasibility, Simulations
D Kπ(π)GSI Darmstadt, Czech Acad. Sci., RezTechn. Univ. Prague
,ω, e+e-
Univ. KrakowJINR-LHE Dubna
J/ψ e+e-
INR Moscow
Hadron ID Heidelberg Univ,Warsaw Univ.Kiev Univ. NIPNE BucharestINR Moscow
GEANT4: GSI
TrackingKIP Univ. HeidelbergUniv. MannheimJINR-LHE Dubna
Design & constructionof detectors
Silicon PixelIReS StrasbourgFrankfurt Univ.,GSI Darmstadt,RBI Zagreb,Krakow Univ. LBNL Berkeley
Silicon StripSINP Moscow State U.CKBM St. PetersburgKRI St. Petersburg
RPC-TOFLIP Coimbra, Univ. S. de Compostela,Univ. Heidelberg,GSI Darmstadt,NIPNE BucharestINR MoscowFZ RossendorfIHEP ProtvinoITEP Moscow
Fast TRDJINR-LHE, DubnaGSI Darmstadt,Univ. MünsterINFN Frascati
Straw tubesJINR-LPP, DubnaFZ RossendorfFZ Jülich
ECAL ITEP Moscow
RICH IHEP Protvino
Trigger, DAQKIP Univ. HeidelbergUniv. MannheimGSI DarmstadtKFKI BudapestSilesia Univ.
MagnetJINR-LHE, DubnaGSI Darmstadt
AnalysisGSI Darmstadt,Heidelberg Univ,
Data Acquis.,Analysis
Project cost (M€)
Total: 675
Buildings: 225.5 SIS100: 70.1 SIS200: 39.6 Coll. Ring: 45.0 NESR: 40.0 HESR: 45.0e-ring: 15.0 Beamlines: 21.0 Cryo, etc: 44.1
SFRS: 40.7CBM: 27.0AP: 8.7Plasma phys.: 8.0p-linac: 10.0PANDA: 28.4pbar targ.: 6.9
Project evolutionOct. 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
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
SIS18 Upgrade 70 MW Connection
Proton-Linac
TDM#
SIS100 Transfer Line SIS18-SIS100
High Energy Beam Lines
RIB Prod.-Target, Super-FRSRIB High+Low Energy Branch
Antiproton Prod.-TargetCR-Complex
HESR & 4 MV e- –CoolingNESR
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-ComplexRIB 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 the International Facility for Beams of Ions and Antiprotons
2,7x1011 /s 238U28+ (200 MeV/u) 5x1012 protons per puls
1x1011/s 238U28+ (0.4-2.7GeV/u) ->RIB (50% duty cycle)
2.5x1013 p (1-30 GeV)3-30 GeV pbar->fixed target10.7 GeV/u 238U -> HADES*
1x1012/s 238U28+
100% duty cyclepbar cooledp (1-90 GeV)
35 GeV/u 238U92+
NESR physicsplasma physics
Experiment Potential
#Construction Tunnel Drilling Machine
General Planning
Civil Construction Production and Installation *SIS200 installation during SIS100 shut down
Kopenhagen 2003
1. Titel 1 min2. Anlage 23. phasediagram 1 4. Hot dense matter 25. qq condensate 16. Filme 27. Pionen Excitation 18. Transport 19. Phasendiagramm 2 10. Observable 211. Dilepton Sonde 0.512. CERES Daten 113. QGP 0.514. NA49 1 15. Transport 116. cc production 1 20 min17. J/psi Vergleich 118. Inmedium K, D 119. Excitation HSD 120. Excit. D-mesons 121. Requirements 122. CBM 1 123. CBM2 2 24. URQMD 125. Collaboration 126. Working packages 127. Costs 128. Schedule 129. Workshop 0 Summe 13
International Accelerator Facility for beams of Ions and Antiprotons
HADES
CBM
The nuclear reaction experiment at the future facility at GSI
A+A at 2-8 AGeV
A+A at 8-40 AGeV
Au+Au @ 25 AGeV central collision
URQMD event,GEANT simulation: B = 1 T
160 p 400 - 400 + 44 K+ 13 K-
-
p
+
midrapidity
80%
60%incl. decay
67%incl. decay
20%
30%
Acceptance
Au+Au 25 AGeV
URQMD event, GEANT simulation
J/ (x105)
e+e-
0e+e-
counts
(x10-4)
cut: pT 1 GeV/c
e+, e- opening angle
J/ (x105)
counts
e+, e- transverse momentum
cut: 10o
without cuts (incl. misident. pions)
with cuts: pt(e+,e-) > 1 GeV/c, lab 25o, > 10o
e+e-
e+e-
J/e+e-
NJ/ = 1.6
DDe+e-+X
e+e-
counts
counts sum
Au+Au 25 AGeV: e+e- invariant mass spectra
PLUTO simulations: 10 Mio. events
signal/background 10
Simulations on open charm detection: D0+K-
performed by V. Friese (GSI)
Assumptions:
• Au+Au at 25 AGeV (<m>: 328 +, 13 K-)• Perfect track finding• Perfect particle identification• No magnetic field• Silicon detector thickness 100 m
Tools:
URQMD event generatorGEANT4 transport code ROOT data analysis
D0
+ +
K-
K-
p + pK
b
bK
Lab CMpair
vz
*
Suppression of combinatorial background by the following cuts:
invariant mass window mD = 1864 25 MeV displaced decay vertex vz > 0 back to back emission in c.m. system (* = 180o) impactparameter bpair = b bK
colinearity of D and decay products (momentum vectors)
Identification of D-mesons (open charm) Example: D0 K-+
Displaced decay vertex D0 K-+
signal
background
S/B
Vertex resolution: vz = 19 m
Cut : vz > 0,3 mm
Cut-efficiency:Signal: 58.0 %background : 2.7 x 10-4
Impact parameters of K- and + at z=0
bpair = bK x b
Cut : bpair < -0,004 mm2
Cut-efficiency:Signal: 90.3 %background: 23.7 %
signal
background
Colinearity (pointing angle)
Cut : p < 5º
Cut-efficiency:Signal: 99.9 %Background : 12.5 %
signal
background
Total efficiency:Signal: 48.4 %background : 5 x 10-6
ev
m
ND
BSSNR
MeV
5,7/0
Sensitivity :
For <D0> = 10-3 (HSD-Model) und m = 10 MeV: 3-limit reached at 1,6 x 106 eventsSignal/Background 1.8
At a reaction rate of 1 MHz (Au+Au central collisions):D0 detection rate (incl. branching ratio): 13.000 / h
Efficiencies, sensitivity and rates