Hadronic Matter at High Baryon Density

Hadronic Matter at High Baryon Density

Claudia Höhne, GSI Darmstadt

2 Claudia Höhne Strongly Interacting Matter under Extreme Conditions, Hirschegg 2010

At the end of this meeting ….

… let’s look into the future:


… near future


… more distant future


… more distant future


Outline

• Introduction & Motivation

• QCD phase diagram → high baryon densities!

→ phase transitions (quarkyonic phase?), CP?

• high baryon density – hadron gas – phase transition?

• multistrange hadrons, centrality dependence of K/ ratio, K/ fluctuations, dileptons, charm production

• CBM experiment at SIS100 and SIS300

• feasibility studies

• detector R&D


The QCD Phase Diagram

[A. Andronic et al., arXiv:0911.4806 ]

• crossover between hadronic and deconfined phase at low B and high T

• freeze-out curve (T,B)

• high precision data from RHIC (and soon LHC)

• equilibration!

• phase diagram at high B ?

• quarkyonic phase?

• phase transition(s)?

• equilibration?

• critical point/ triple point?

• need for high precision data including rare probes!

A. Andronic et al., Nucl. Phys. A 772, 167 (2006).


Future explorations

complete scan of the QCD phase diagram with modern, 2nd generation experiments on the horizon!

30A GeV

• RHIC beam energy scan- evolution of medium properties- “turn-off” of established signatures- search for CP and PT

• NA61 at SPS (2007 acc. by SPSC)- search for CP and PT in energy-system size scan

• both essentially limited to high yield observables- RHIC: energy dependent

• FAIR and NICA- new accelerator projects- FAIR: high intensities! → rare probes!

Field driven by experimental data!


Chemical freeze-out: a different view

• high (net-)baryon and energy densities created in central Au+Au collisions

beam energy

max. /0

max [GeV/fm3]

time span

~FWHM

5 AGeV 6 1.5 ~ 8 fm/c

40 AGeV 12 > 10 ~ 3.5 fm/c

[J.

Ra

ndru

p, J

. C

leym

ans

PR

C7

4, 0

4790

1 (2

006

)]


Limiting temperature at √sNN ~ 10 GeV

• chemical freeze-out (fit T, B, V): temperature saturates for √sNN > 10 GeV although energy density (and initial T) still increases

→ deconfinement phase boundary reached, additional energy goes into heating the QGP

• occurs at the same energy at which mesons start to carry the larger part of the entropy

[A. Andronic et al., Phys. Lett. B 673 (2009) 142] [H.Oeschler et al., J.Phys.G 32, 223 (2006)]

s/T

3

SIS

100

SIS

300

SIS

100

SIS

300


Multistrange Hadrons

SIS

100

SIS

300

• thermal equilibration also at low energies (high B) in particular concerning multistrange hadrons?

[A. Andronic et al., Phys. Lett. B 673 (2009) 142]


HADES: Sub-threshold - production

[HADES: PRL103, 132301, (2009)]

YK

[HADES: arXiv: 0911.0516]

Ar+KCl reactions at 1.76A GeV

• - yield by appr. 1 order of magnitude higher than thermal yield

• strangeness exchange reactions like

(Y=,) ?


K/ ratio – centrality dependence

• K/ ratio in central Pb+Pb (Au+Au) collisions well described by thermal model

• centrality dependence?[PHENIX, PRC 69 (2004) 034909][STAR, PRC79 (2009) 034909]• high energies: fast rise and

saturation behavior well understood in terms of percolation [1] or Core-Corona model [2]

[1] CH, F. Pühlhofer, R. Stock, Phys. Lett. B 640 (2006) 96[2] K.Werner, PRL 98, 152301 (2007)


K/ ratio – centrality dependence• lower energies?

→ same shape of centrality dependence for √sNN > 17 GeV→ changing dependence for lower energies?!→ relation to hadron rescattering/ freeze out at phase transition?

• other strangeness carriers – in particular , ?

[black & red lines: CH, F. Pühlhofer, R. Stock, PLB 640 (2006) 96]

[KA

OS

, JPG

31 (2005) S

693][E

802, PR

C 60 (199

9) 044904]

[NA

49 preliminary, Q

M09

]


• particle ratio fluctuations as sign for 1st order phase transition or CP?

• no data below 20 AGeV beam energy

• interpretation of measurements under discussion

• one suggestion:

K/ fluctuations

[NA49, Phys.Rev.C79:044910,2009]scaling with Volume (Nch) or number of K (NK) in acceptance?

→ test with centrality dependence!


K/ Fluctuations

• different scaling for energy and centrality dependences

• additional contributions from fluctuating cluster sizes/ core-corona contributions?!

• K/ fluctuations might be dominated by number of kaons

NN

NN

N

N

N

N

K

K

K

KKdyn

,cov2

varvar22

/

[D. Kresan, CPOD 2009, arXiv:0908.2875]

22mixeddatadyn

NA49 preliminary


Dileptons[C

ER

ES

: E

ur.P

hys.

J.C

41,

47

5 (2

005)

]

• dileptons as direct probe of the high density phase

• CERES at 40 and 158 AGeV beam energy: excess higher at lower energy → importance of baryon density!

• HADES at SIS18: study coupling to baryons!

preliminary

explains C+C!

HADES, arXiv: 0907.3690 – QM09


Charm propagation

[HSD: O. Linnyk et al., Int.J.Mod.Phys.E17, 1367 (2008)] [SHM: A. Andronic et al., Phys. Lett. B 659 (2008) 149]

Propagation of produced charm quarks in the dense phase –quark like or (pre-)hadron like?

• charmonium to open charm ratio as indicator – measure both!• indications of collectivity?

• first charm measurements in A+A below 158 AGeV!

• aim at detailed information including phase space distributions, flow!


CBM @ FAIR

+ HADES

CBM and HADES at SIS 100 and SIS 300

• systematic exploration of high baryon density matter in A+A collisions from 2 – 45 AGeV beam energy with 2nd generation experiments

• explore the QCD phase diagram, chiral symmetry restauration


Module 0:SIS100

Module 1:CBM Cave,APPA hall

Module 2:SFRS + R3BModule 3:

Anti-proton facilityModule 4:Low-E NUSTAR, NESR, FLAIR, APPA-cave

Module 5:RESR

HADES and CBM startversion at SIS 100


Nuclear equation-of-state: What are the properties and the degrees-of-freedom of nuclear matter at neutron star core densities? Hadrons in dense matter: What are the in-medium properties of hadrons? Is chiral symmetry restored at very high baryon densities? Strange matter: Does strange matter exist in the form of heavy multi-strange objects? Heavy flavor physics: How ist charm produced at low beam energies, and how does it propagate in cold nuclear matter?

s

s

s

uud? Λ

Λ

Nuclear matter physics at SIS 100


CBM: Physics topics and Observables

Onset of chiral symmetry restoration at high B

• in-medium modifications of hadrons (,, e+e-(μ+μ-), D)

Deconfinement phase transition at high B • excitation function and flow of strangeness (K, , , , )• excitation function and flow of charm (J/ψ, ψ', D0, D, c)• charmonium suppression, sequential for J/ψ and ψ' ?

The equation-of-state at high B

• collective flow of hadrons• particle production at threshold energies (open charm)

QCD critical endpoint• excitation function of event-by-event fluctuations (K/π,...)

Systematics & precision!!

→ characterization of the created medium!

CBM Physics B

ook

submitt

ed!


Particle multiplicity ∙ branching ratio for min. bias Au+Au collisions at 25 GeV (from HSD and thermal model)

SPS Pb+Pb 30 A GeV

Particle multiplicities


The CBM experiment• tracking, momentum determination, vertex reconstruction: radiation hard silicon pixel/strip detectors (STS) in a magnetic dipole field

• hadron ID: TOF (& RICH)• photons, 0, : ECAL

• electron ID: RICH & TRD suppression 104

• PSD for event characterization• high speed DAQ and trigger → rare probes!

• muon ID: absorber + detector layer sandwich move out absorbers for hadron runs

RICHTRD

TOF ECAL

magnet

absorber +

detectorsSTS + MVD


STS tracking – heart of CBM

Challenge: high track density: 600 charged particles in 25o @ 10MHz

Task

• track reconstruction: 0.1 GeV/c < p 10-12 GeV/c p/p ~ 1% (p=1 GeV/c)

• primary and secondary vertex reconstruction (resolution 50 m)

• V0 track pattern recognition

c = 312 m

radiation hard and fast silicon pixel and strip detectors

self triggered FEE

high speed DAQ and trigger

online track reconstruction!

fast & rad. hard detectors!


Parallelization in CBM Reconstruction !

Vector SIMD

MultiThreading

NVIDIA CUDA

OpenCL

STS + + + +

MuCh + +

RICH + +

TRD + +

Vertexing +

Open Charm Analysis

+

+ March 2009+ October 2009

DELL Server with: DELL Server with: • Core i7/NehalemCore i7/Nehalem 22x(Xeon X5550 44x2.66 GHz, 8 MB L3 cache)• DDR3-1333 36 GB36 GB main memory• NVIDIA NVIDIA GTX 295 2x240 FPUs2x240 FPUs, 1792 MB• optional LRBLRB

• fast event reconstruction is a must for CBM!


CBM feasibility studies

• feasibility studies performed for all major channels including event reconstruction and semirealistic detector setup

J/ J/

di-electrons di-muons

' '

c

1010 events

D0


Di-electrons at SIS300

pt < 0.2 GeV/c

• CBM has acceptance for di-electron pairs down to lowest pt and Minv

• feasibility study for central Au+Au collisions, 25 AGeV, 200k events

detected pairs


Feasibility studies for CBM at SIS 100• charm production in pC collisions with 30 GeV/c p-beam!

• open charm: STS + dipole magnet, TOFcharmonium: STS, dipole magnet, reduced muon detector

• study charm production at threshold, cold nuclear matter effects, reference data for later A+A collisions

4 cut

eff = 11.6 %

6 J/ψ recorded in 1010 events (b=0) (3·104 J/ψ per week)

J/ → +-


Sensor development:double-sided micro-strips, stereo angle 15o, pitch 60 μm300 μm thick, bonded toultra-thin micro-cables,radiation hardness

STS in thermalenclosure

Detector planes: ultra-light weight ladder structure

Prototypes (sensors, electronics, cables for beam tests:

Development of the Silicon Tracking System (STS)


D1, D2

tracker boards Q2, Q4, Q6

beam

boards D1 + D2

rotation around vertical axis 20 deg

STS demonstrators in testbeam @ GSI (Sep ’09)

with 4 n-XYTER chips fully reading out one CBM baby detector

reference tracking telescope

with 3 or 4 stations


Beam spot in Q6

… further analysis ongoing


Monolithic Acitive Pixel Sensors in commercial CMOS process1010 m2 pixels fabricated, > 99%, x ~ 1.5 – 2.5 m

Micro Vertex Detecor (MVD) DevelopmentArtistic view of the MVD

• mechanical system integration • material for cooling!→ material budget!• vacuum compatibility

die thinned to 50 mglued to support.IPHC, Strasbourg (M. Winter et al.)


Sensors for the MVD

Monolithic Active Pixel Sensors(MAPS, also CMOS-Sensors)

• Invented by industry (digital camera)

• Modified for charged particle detection since 1999 by IPHC Strasbourg

• Also foreseen for ILC, STAR…

~ 1 µm

MAPS(2009)

~ 0.05% X0

1.5µm

MAPS(2003)

~ 0.1% X0

Digital camera with 8.2 MPixel – CMOS MAPS

Topic

Single point resolution

Material budget

Rad. hard. non-io.

Rad. hard. io

CBMwish list

~ 5µm

few 0.1% X0

~1012 neq/cm² > 3x1013 neq/cm²

Time resolution

> 1 MRad 200 kRad

>1013 neq/cm²

> 3 Mrad

~ 50 µs ~ 1 ms< 30 µs


The MVD-demonstrator test @ CERN (Nov. 2009)

• First test of MVD demonstrator at CERN-SPS (Nov ’09)

• two single sided modules operated in coincidence “MVD telescope”, stations can be correlated by time stamps

• noise of the modules was 25-35 electrons (as expected from lab)

• data analysis ongoing

4 x MIMOSA-20 4 x 640 x 320 pixel 30 x 30 µm² pixel Serial analog readout Vacuum compatible cooling


RICH development

• develop robust but very efficient and high performant RICH detector based on industrial available components

• adopt self-triggered readout electronics

mirror + mount

MAPMT (H8500, Hamamatsu)


Hamamatsu H8500

MAPMT beamtest for RICH @ GSI (Sep ’09)

• plexiglass radiator for Cherenkov light generation by protons

• self-triggered readout electronics based on the n-XYTER adopted to the PMT readout (attenuation!): negligible noise level if requiring beam coincidence

3.5 hits/events

→ single photon counting with self triggered readout!

→ further analysis ongoing


STSSTSGEMGEMRICHRICH

DABC + Go4, Slow Control DABC + Go4, Slow Control

TriggerTrigger S3+S4S3+S4

CBM beamtest @ GSI (Sep 2009)

• combined beam time CBM & PANDA • 9 days of ~ 2 hours beam per day • protons, 2.0 GeV, ~ 104 p/s


DAQ in September 2009 Test Beam

FEB4nxBT

ROC EthA

BSYNC-S

AUX

FEB4nxBT

ROC EthA

BSYNC-S

AUX

ROC EthA

BSYNC-S

AUX

BEAM.

DABC

OnlineAnalysi

sGo4

discr

RICH/MAPMT ROC

EthA

BSYNC-M

AUX

FEB1nxGenFEB1nxGen

GEM2VECC

Beam Tag/Trigger

ROC EthA

BSYNC-S

AUX

ROC EthA

BSYNC-S

AUX

FEB1nxGenFEB1nxGen

FEB1nxGen

D1

D2

GEM1VECC

FEB1nxGen

6 ROC's8 FEB's12 n-XYTER

• system test!

• self-triggered FEE for all detectors, event building based on time stamps


CBM@FAIR – high B, moderate T:

• exploration of QCD phase diagram at high baryon densities at SIS 100 and SIS 300 (2-45 AGeV beam energy)

• together with HADES unique possibility of characterizing properties of baryon dense matter

• implementation of increasingly realistic detector response in simulations, parallelization of event reconstruction, first physics performance studies

• detector R&D ongoing

• several beamtests in 2009:RPCSTS, GEM, RICHMVD

Summary

[A. Andronic et al., arXiv:0911.4806 ]


CBM collaboration

Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. Petersburg

China:Tsinghua Univ., BeijingCCNU WuhanUSTC Hefei

Croatia:

University of SplitRBI, Zagreb

Portugal: LIP Coimbra

Romania: NIPNE BucharestBucharest University

Poland:Krakow Univ.Warsaw Univ.Silesia Univ. KatowiceNucl. Phys. Inst. Krakow

Ukraine: INR, KievShevchenko Univ. , Kiev

Univ. MannheimUniv. MünsterFZ RossendorfGSI DarmstadtUniv. WuppertalCzech Republic:

CAS, RezTechn. Univ. Prague

Germany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. Frankfurt

Hungaria:KFKI BudapestEötvös Univ. Budapest

India:Aligarh Muslim Univ., AligarhIOP BhubaneswarPanjab Univ., ChandigarhGauhati Univ., Guwahati Univ. Rajasthan, JaipurUniv. Jammu, JammuIIT KharagpurSAHA KolkataUniv Calcutta, KolkataVECC KolkataUniv. Kashmir, SrinagarBanaras Hindu Univ., Varanasi

Norway:Univ. Bergen

Kurchatov Inst. MoscowLHE, JINR DubnaLPP, JINR Dubna

Cyprus: Nikosia Univ.

56 institutions, > 400 members Split, Oct 2009

LIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP, Moscow State Univ. St. Petersburg Polytec. U.

Korea:Korea Univ. SeoulPusan National Univ.

France: IPHC Strasbourg

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Hadronic Matter at High Baryon Density