future physics with cbm paweł staszel jagiellonian university physics motivation detector concept...

Future Physics with CBM

Paweł StaszelJagiellonian University

Physics motivation Detector concept Feasibility study Status

Paweł Staszel 31st Mazurian Lakes Conference, Piaski 1.09.2008 2

CBM (Compressed Baryonic Matter)

net-baryon density created in central Au+Au


Diagram fazowy QCD


QCD Phase Diagram scan with A+Acollisions

Y.B Ivanov et al., Phys. Rev. C 73, 044904 (2006)

3 component hydrodynamics + hadron gas EOS:

Critical Point reached at trajectory for ~30 AGeV (s

NN=7.74)

Phase Boundary reached already at ~10 AGeV (s

NN=4.72)

How to explore interesting regions of the QCD Phase Diagram

Lattice QCD calculations:Fedor & Katz,Ejiri et al.

Freeze-out phase can be studied by measurement of „soft” hadrons production (bulk observables)

Information about earlier phases is carried by rare probes:

• High pT particles

• Particles decaying into leptons• Particles build up of heavy quarks (J/ψ, D, Λ

c ....)

and by collective motion (flow) of the created soft medium. (e .g. v

2 is

sensitive to the quanta interaction just after the medium formation)

large advantage from simultaneous flow measurement of “ordinary” hadrons and rare probes

Future projects to explore phase diagram at large

RHIC energy-scan ................................ bulk observablesNA61@SPS ......................................... bulk observables

MPD@NICA ........................................ bulk observables

CBM@FAIR ........................................ bulk and rare observables

mailto:NA61@SPS


Experymental arguments for Phase Transition at low SPS energy

NA49 (QM 2004)

None monotonic behaviour of K+/+ ratio

Effective temperature shows plateau in the range of SPS energy


Kaon spectra versus hadronic models

UrQMD and HSD models can describe p+p and light Ion data (C+C).

Description of kaon spectra in central Au+Au and Pb+Pb requires contribution from strong parton-parton interactions in the early phase

E. Bratkovskaya et al. PRL 92, 032302 (2004)


Hadrons in dense medium (->+-)

NA60, Nucl. Phys. A 774 (2006) 67

broadening of spectral function (Rapp-Wambach)

contradiction with mass drop scenario (Brown-Rho scaling)

excess by factor of 4 over the “cocktail” with 25% systematic uncertainty !


Updates on +- results

Good pair excess description for M > 1 GeV assuming thermal QGP (q+qbar → contribution

J. Rappert et al. PLB 100, 162301 (2008)

For M up to ~0.9 MeV Teff

scales with

M → radial flow on hadronic levelFor M > 1 GeV partonic contribution


Open charm in dense medium

A. Mishra et al., Phys. Rev. C 69, 015202 (2004)

Reduction in the effective mass of D-meson can open D-Dbar decay channel for charmonium states → possible scenario for the J/Ψ suppression, CBM=> simultaneous measurement of J/Ψ and D-mesons


J/Ψ suppression

Anomalous J/ψ suppresion (AS) on SPS, L – effective path in medium

NA50, QM 2005

NA60 evidenced same effect in In+In

Better scaling is obtained in Npart

; onset already at Npart

~90,

At lower energies (larger μB) one can expect onset of AS for more central collisions

→ dependency on energy density and μB Important measurement of open charm to verify other scenarios


Event-by-event fluctuations

[NA49 collaboration, arXiv:0810.5580v2 [nucl-ex]]

• observation might become enormously difficult

• correlation length of sigma field, may become rather small for a finite lifetime of the fireball

• large acceptance needed!

2

2

pt

pt

pt zN

Z=Φ

N

=ittipt

ttpt

pp=Z

pp=z

1

[Stephanov, Rajagopal, Shuryak, PRD60, 114028 (1999)]

fluctuations, correlations with large acceptance and particle identification

K. Grebieszków on Thursday

http://arxiv.org/abs/0810.5580v2


CBM: Physics topics and Observables

Onset of chiral symmetry restoration at high B and tracing medium properties in time • 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' ? corelated with open charm ?

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,...)

predictions? clear signatures?→ be prepared to measure "everything": bulk particles and rare probes → probing medium with known overall characteristics→ systematic studies! (pp, pA, AA, energy)


CBM Detector (->e+e-)

TRDs(4,6,8 m)

STS ( 5 – 100 cm)


CBM Detector (->+-)

beam

ABSORBER(1,5 m)

TRDs(4,6,8 m)

TOF(10 m)

ECAL(12 m)

STS ( 5 – 100 cm)

magnet

PSD(~15 m)


Silicon Tracking System – heart of CBM

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

Tasks:• 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!


Silicon Tracking Performance

momentum resolution1.3%

(tracks pointing to primary vertex)

[%

]

p [GeV/c]

central Au+Au 25 AGeV (UrQMD)

700 reconstructed tracks

X-Z view

Y-X view

<1 % ghost tracks

96%

[%

]

p [GeV/c]

reconstruction efficiency

momentum resolution

Cellular Automaton and Kalman Filter,

50 ms on Pentium 4

A. Bubak, 19:40 on Wednesday

Hyperons: PID from decay topology in STS


Simulation: bulk particles and hyperons

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

y0 0.5 1 1.5 2 2.5 3 3.5 4

[G

$V/c

]T

p

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

y0 0.5 1 1.5 2 2.5 3 3.5 4

[G

$V/c

]T

p

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

y0 0.5 1 1.5 2 2.5 3 3.5 4

[G

$V/c

]T

p

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

incl. TOF

10 35AGeV

Λ Ξ Ω


ρ,ω,φ

ρ, ω, φ J/ψ, ψ'

Signal and background yields from physics event generators (HSD, UrQMD) Full event reconstruction based on realistic detector layout and response

Feasibility studies for dilepton measurements

Electron id:RICH and TRD

Muon id:segmented hadron absorber+ tracking system

125(225) cm iron,15(18) det. layers

π suppression:

factor 104

dominant background: e from π0 Dalitz

125 cm Fe: 0.25 ident. /event

dominant background: μ from π, K decay (0.13/event)

J/ψ

200k events 4 1010 events

4 108 events 3.8 1010 events


STS: 8 stations double-sided Silicon micro-strip sensors (8 0.4% X0)

MVD: 2 stations MAPS pixel sensors (0.3% X0, 0.5% X

0) at z = 5cm and 10cm

no K and π identification, proton rejection via TOF

~ 12k D+ + 26k D- 10 weeks data taking reduced interaction

rate 105/s:

Open charm measurement

D → K π π, cτ= 317 μm109 centr. ev.

eff = 2.6%

S/B = 2.4 (D-) 1.1 (D+)

D0 → K π, cτ= 123 μm1010 centr. ev.

eff = 4.4%

S/B = 6.4 (D0) 2.1 (D0)

_

and~ 7k D0 + 20k D0


Performance summary

Maximum beam intensity: 109 ions/s10 weeks of Au-beam at 25 AGeV beam energy

• Minimum bias collisions can be recorded with 25kHz→ unlimited statistics for bulk observables (K, )→ 106 mesons, 108 , 106 (spectra, flow, correlations, fluctuations)

• Open charm trigger will allow for 100kHz → 104 open charm hadrons• Charmonium trigger with max. beam intensity: 10MHz→ 106 J/• (charm production, spectra, flow measurement)


Status

CBM Collaboration undergoes (phase) transition

simulation → prototyping


Double and triple GEM detectors2 Double-sided silicon microstrip detectors Radiation tolerance studies for readout electronics Full readout and analysis

chain:

Front-end board with self-triggering n-XYTER chip Readout controller

Data Acquisition System

online

offline

Go4

AnalysisDetector

signals

Successful test of CBM prototype detector systems with free-streaming read-out electronics using proton beams at GSI, September 28-30, 2008

GSI and AGH Krakow VECC Kolkata KIP Heidelberg


CBM hardware R&D

RICH mirror

n-XYTER FEB

Silicon microstrip detector

MVD: Cryogenic operation in vacuum RPC R&D

Forward Calorimeter

GEM

dipole magnet


90 pages, available at www.gsi.de/fair/experiments/CBM

CBM Progress Report 2008

Content:• Micro Vertex Detector

• Silicon Tracking System

• Ring Imaging Cherenkov Detector

• Muon System

• Transition Radiation Detectors

• Resistive Plate Chambers

• Calorimeters

• Magnet

• FEE and DAQ

• Physics Performance

• Software and Algorithms


CBM CollaborationChina:Tsinghua Univ., BeijingCCNU WuhanUSTC Hefei

Croatia:

University of SplitRBI, Zagreb

Portugal: LIP Coimbra

Romania: NIPNE BucharestBucharest University

Poland:Krakow Univ.Warsaw Univ.Silesia Univ. KatowiceKraków AGH(Inst. Nucl. Phys. Krakow)

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

Ukraine: INR, KievShevchenko Univ. , Kiev

Univ. MannheimUniv. MünsterFZ RossendorfGSI Darmstadt

Czech Republic:CAS, RezTechn. Univ. Prague

France: IPHC StrasbourgGermany: Univ. Heidelberg, Phys. Inst.Univ. HD, Kirchhoff Inst. Univ. Frankfurt

Hungaria:KFKI BudapestEötvös Univ. BudapestIndia:Aligarh Muslim Univ., AligarhIOP BhubaneswarPanjab Univ., ChandigarhGauhati Univ., Guwahati Univ. Rajasthan, JaipurUniv. Jammu, JammuIIT KharagpurSAHA KolkataUniv Calcutta, KolkataVECC Kolkata

Univ. Kashmir, SrinagarBanaras Hindu Univ., Varanasi

Korea:Korea Univ. SeoulPusan National Univ.Norway:Univ. Bergen

Kurchatov Inst. MoscowLHE, JINR DubnaLPP, JINR DubnaCyprus:

Nikosia Univ.

55 institutions, > 400 members

Dubna, Oct 2008

Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. Petersburg


Hadrons in dense medium (->e+e-)

Top SPS: excess of e+e- pairs around 0.5 GeV (by factor of ~2.8)40AGeV: the excess rised up to ~4 → strong dependency on

B

Rapp-Wambach – in-medium modification

Rapp: “dropping mass” according to Brown-Rho scaling scenario

Thermal model


Elliptic flow at RHIC (√SNN

= 200 GeV)

gPHENIX, PRL.98:162301,2007

baryons mezonsn 3 2

KET = m

T - m

• all particles flow (even these with charm!) → strong interactions

• scaling if taking the underlying number of quarks into account!→quark combine to hadrons at a later stage (hadronization via coalescence)

data can only be explained assuming a large, early built up pressure in a nearly ideal liquid (low viscosity!)

→ sQGP

Elliptic flow at SPS

data at top SPS support hypothesis of early development of collectivity• influence of hadronic rescattering phase, resonance decay? • lack of complete thermalization, viscosity effect?• larger pt-range needed

Pb+Pb collisions, √sNN

= 17.3 GeV

[NA49, G. Stefanek, PoS CPOD2006:030,2006]

Paweł Staszel Konwersatorium PTF oddział katowicki, Katowice 25.02.2009 33

In parallel, in time steps of 10-100s in SIS100/300 proton/heavy ion beams are accelerated to high energy: 90GeV – protons, 45GeV – heavy ions

High energy proton and heavy ion beam are gradually extracted for HADES+ and CBM experiments


Mapping the QCD phase diagram with heavy-ion collisions

net baryon density: B 4 ( mT/2h2c2)3/2 x [exp((B-m)/T) - exp((-B-m)/T)] baryons - antibaryons

Lattice QCD calculations:Fedor & Katz,Ejiri et al.

SIS300

future physics with cbm paweł staszel jagiellonian university physics motivation detector concept...

Documents

qcd phase diagram scan

phase transition

phase boundary

simultaneous measurement

bulk observablescbm

bulk observablesna61

effective mass of d

bulk observables mpd