Nucleus-nucleus collisions at the future facility in Darmstadt -

Compressed Baryonic Matter at GSI

Outline:

Dense baryonic matter: fundamental physics Experimental observables Technical challenges and (possible) solutions

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

B 3-80 , T 130 MeV

Fundamental questions:

Equation-of-state at high densities: stability of neutron stars, supernova dynamics

deconfinement

In-medium hadron properties: chiral symmetry restoration, origin of hadron masses?

Creating high baryon densities in the laboratoryby heavy-ion collisions

Transport calculationsB. Friman, W. Nörenberg, V.D. Toneev Eur. Phys. J. A3 (1998) 165

SIS300

Pion multiplicities per participating nucleons

SIS100/300

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 (CERN Courier Oct. 2003)

SIS100300

SIS100300

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”

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

SIS300

gasliquid

coexistence

C. R. Allton et al, hep-lat 0305007

Lattice QCD : maximal baryon number density fluctuations at TC for q = TC (B 500 MeV)

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 ??

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

Measure spectral functions of vector mesons via their decay into electron-positron pairs (penetrating probes!)using Ring Imaging Cherenkov detectors

NA45/CERES @ CERN-SPS

CH4 radiator gas: thr= 32

HADES @ GSI

C4F10 radiator gas: thr= 18.3UV-det.: fast CsI cathode

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 ?

Anomalous suppression of charmonium (J/) ???

central collisions 25 AGeV Au+Au 158 AGeV Pb+Pb

J/ multiplicity 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]

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

SIS18 SIS100/

300

Meson production in central Au+Au collisionsW. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl. Phys. A 691 (2001) 745

Observables:p, , K, , , , , , , , D, J/(3-diff. cross sect., correlations, dileptonic decays)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 GeVp+p collisions from 8 to 90 GeVBeam energies up to 8 AGeV: HADESAccelerator:SIS300High beam intensity and duty cycle,Excellent beam quality, no halo !Available for several month per year

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-

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, π, η, and muons: electromagn. calorimeter (ECAL)

High speed data acquisition and trigger system

CBM in GEANT4

CBM 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. Santiago de Com.,Univ. Heidelberg,GSI Darmstadt,NIPNE BucharestINR MoscowFZ RossendorfIHEP ProtvinoITEP Moscow

Fast TRDJINR-LHE, DubnaGSI Darmstadt,Univ. MünsterINFN Frascati

Straw tubesJINR-LPP, DubnaPNPI GatchinaFZ RossendorfFZ Jülich

ECAL ITEP Moscow GSI Darmstadt

RICH IHEP Protvino GSI Darmstadt

Trigger, DAQKIP Univ. HeidelbergUniv. MannheimGSI DarmstadtJINR-LIT, DubnaKFKI BudapestSilesia Univ.

MagnetJINR-LHE, DubnaGSI Darmstadt

AnalysisGSI Darmstadt,Heidelberg Univ,

Data Acquis.,Analysis

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 (2004-2005)

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

New call EU FP6 (opened Nov.03, closed Mar04):

• Design of new facilities • Construction of new facilities

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

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. MarburgUniv. MünsterFZ RossendorfGSI Darmstadt

   

Russia:CKBM, St. PetersburgIHEP ProtvinoINR TroitzkITEP MoscowKRI, St. PetersburgKurchatov Inst., MoscowLHE, JINR DubnaLPP, JINR DubnaLIT, JINR DubnaPNPI GatchinaSINP, 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