The CBM heavy-quark program
description
Transcript of The CBM heavy-quark program
The CBM heavy-quark program
NEW TRENDS IN HIGH-ENERGY PHYSICS(experiment, phenomenology, theory)
Alushta, Crimea, Ukraine, September 3 - 10, 2011
Iouri VassilievCBM Collaboration
Physics case: Exploring the QCD phase diagram
Projects to explore the QCD phase diagram at large μB:
RHIC energy-scan, NA61@SPS, MPD@NICA bulk observables
CBM@FAIR/SIS-300 bulk and rare observables, high statistic!
SPS-CERN
CBM
LHC RHIC
The equation-of-state at high B
• collective flow of hadrons• particle production at threshold energies (open charm) 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, for J/ψ and ψ' ?
QCD critical endpoint• excitation function of event-by-event fluctuations (K/π,...)
Onset of chiral symmetry restoration at high B
• in-medium modifications of hadrons (,, e+e-(μ+μ-), D)
21/04/23 I.Vassiliev, CBM 3
SPS Pb+Pb 30 A GeV
The mission:
SIS-300 SIS-100
D0, D+, Ds+ , c , D*
D0, D+, J/
P.SengerJ/,
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HSD simulations
Charm production at threshold
• J/ and open charm suppression measured
• charmonium in hot and very dense matter?
• open charm in hot and very dense matter?
D
Nuclear effects at low energy
21/04/23 I.Vassiliev, CBM 5
central Au+Au 25AGeV791 mc track 697 recoRef primary eff = 94.6%
80 mslxir039
up to 107 Au+Au reactions/sec (J/ψ) determination of (displaced) vertices with high resolution ( 50 m) identification of leptons and hadrons fast and radiation hard detectors self-triggered readout electronics high speed data acquisition and online event selection
Finder: 80 msFitter: 1.6 msPV : 51.2 msK0
S : 32.8 msTotal 165.6 ms/16 cpu
697 reconstructed tracksRef. prim. eff = 96%All set eff = 88%dp/p = 1.2%
700 160 p 53 K32 KS
~1 -
0.022 -
front view
SIMDized tracking
Online: track finder, track fitter, PV finder, V0 finder, -, - finder
e+/-
π+/-
RICH + TRD:e identification efficiency 85 % π-suppression 104
Rings: up to 100 per event~ 6cm diameter~ 20 photo electrons
finding eff. 95.3%multi-anode PMT
glass mirror with Al+MgF2 high-rate TRD
Charmonia (di-electron channel)
Signal and background yields from physics event generators (HSD, UrQMD) Full event reconstruction based on realistic detector layout and response
Electron id:RICH and TRD
π suppression: factor 104
dominant background: e from π0 Dalitz
4 1010 events
J/ψ
Charmonia (di-electron channel)
Muon detection
low-mass vector mesonlow-mass vector mesonmeasurementsmeasurements
≡ 7.5 λII
≡ 13.5 λI
Fe
20 20 2
0 30
35 1
00 cm
JJ//measurementsmeasurements
256 pads 3.5×8 mm2
Straw tubes
GEM detectors
trigger
J/ψ, ψ'
Signal and background yields from physics event generators (HSD, UrQMD) Full event reconstruction based on realistic detector layout and response
3.8 1010 events
6 J/ψ recorded in 1010 events (b=0) (20 J/ψ per hour)
J/ψ → μ+μ-
p+C 30 GeV
Au+Au 25 AGeV
Charmonia (di-muon channel)
Open charm. 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…
CBM
wish list
MAPS*
(2003)
MAPS*
(2009)
Single point res. ~ 5 µm 1.5 µm 5 µm
Material budget < 0.3% X0 ~ 0.1% X0 ~ 0.05% X0
Rad. hard. non-io. >1013 neq 1012 neq/cm² >3x1013 neq
Rad. hard. io > 3 Mrad 200 krad > 1 Mrad
Time resolution < 30 µs ~ 1 ms ~ 30 µs
Best values reached
Monolithic Acitive Pixel Sensors in commercial CMOS processCBM: 5 µm single point resolution
Micro Vertex Detecor (MVD) Development
first demonstrator tested in beam!
• first station 5cm downstream of target
• high position resolution!
Chip-on-polyamide
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: full CBM sensor, ultrathin cables
Development of the Silicon Tracking System (STS)
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MC RECO
XY Rear View
e+
e-
p
p
K-
-
+
Reconsruction time << 1ms
e+
e-
p
p
K-
-
+
MC
p+C 30GeV SIS-100
-electrons
50 pile up + -electrons by 100k protons
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Primary vertex reconstruction
pC 30 GeV
4.5 tracks central, 1 track mbias
K-
+
+
2geo
D+
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Open charm at SIS-100Invariant mass spectra
3 cut 4 cut
MD+ HSD=2.710-8
BR = 0.095
with PV BG suppressed 10-30 times!
eff = 13.2 % eff = 11.6 %
p+C 30GeV D+ K- ++
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Invariant mass spectra
with PV BG suppressed
p+C 30GeV
D0 K- ++-
MD0 HSD = 2.9(8.8)10-8
BR = 7.7%Eff = 1.7%
K-
+
-
2geo
D0
+
3 cut
1012 central events
Primary vertex reconstructionAu+Au @ 25AGeV
450 tracks central100 tracks mbias
50 ms
450 primary tracks
IR: 0.1MHz = 300 Au ions-electrons!
479
12389
t = 30 s
Open charm (Au+Au @ 25 AGeV)z-vertex reconstruction
D0K-+
KK--
+
Out
er a
cc.
Inne
r 2
prim > 3
2geo < 3 Eff =10.4%
K0S
eff~12.0%
2prim > 3
2geo < 3
q>0 proton mass
Open charm Reconstruction Quality Control
22
Open charm Reconstruction Quality Control
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Strategy: background suppression keeping maximum of efficiency
single track parameters based cuts: χ2
prim impact parameter value 6.0-7.5 IP impact parameter cut (upper value) 0.5 mm protons ID by TOF track transverse momentum pt > 0.3 GeV/c (D0 only)multiple track (particle) parameters based cuts: χ2
GEO geometrical constrained fit 3.0 χ2
TOPO topological constrained fit 2.0-3.0 charm particle to primary vertex DCA < 20(30) m Zvertex < 2(3.5) mm c
21/04/23 I.Vassiliev, CBM 2424
χ2prim impact parameter value 6.5-7.5
2 = r2/2
r
pv
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χ2geo geometrical constrained fit 3.0
K
2geo
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Zvertex geo > 350 m
27
χ2topo topological constrained fit 2.0-3.0
PVK-
+
+2geo
2topo
D+2
prim
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charm particle impact parameter < 20 m
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Zvertex < 2 mm (new cut)
Duplets cut
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Invariant mass spectra Au+Au @ 25 AGeV
1.6k
600
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Invariant mass spectra Au+Au @ 25 AGeV
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Invariant mass spectra Au+Au @ 25 AGeV. C+C @ 25AGeV
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D0+D0 D++D- Ds+ c
+
decay channel K-+ K-+ + K-K+ + p K-+
MHSD1.5·10-4 4.2·10-5 5.4·10-6
MSM8.2·10-4 8.4·10-5 1.4·10-4 4.9·10-4
BR(%) 3.8 9.5 5.3 5.0
geo. acc.(%) 29.2 40.1 32.8 71
z-resolution (m) 52 56 60 69
total eff. (%) 3.95 4.75 1.0 0.05
m (MeV/c2) ~11 ~11 ~11 ~11
S/B2 0.16/0.5 1.24/2.5 5.0 0.6
Yield/1012mb HSD 14k+41k 47k+89k 0.7k
Yield/1012mb SHM 78k+225k 95k+179k 19k 3.2 k
Open charm properties table (25AGeV)
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Open Charm Triggers
D0 K-+ (K-++-) D+ K-+ +
Ds K- K+ +
c p K- +
DVT
PVK-
+
+
D+
2geo
2topo
Background Background
D+2
prim
DKT
Open Charm Trigger-algorithm
L1CATrackFinder SIMD
L1KFTrackFitter SIMD
Charm Track Candidates Selection χ2prim > N
Charm Pairs χ22geo
< 3.0, zv <1 cm χ2
topo < 3.0, minv > 1.3 GeV
Charm Triplets χ23geo+topo < 3.0 ☺
D+c Ds
☺D0☻
☻
RFmb = 125RFcen = 14
accepted
acceptedrejected
N = 3
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Detached Vertex Trigger:
RFmb = 125RFcen = 14
CBM timeline 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
R&D detectors & read-out systems
construction detectors & read-out systems
installation, commissioning
first data taking
21/04/23 I.Vassiliev, CBM 38
Croatia:Croatia: RBI, ZagrebSplit Univ.
China:China:CCNU WuhanTsinghua Univ. USTC Hefei
Czech Republic:Czech Republic:CAS, RezTechn. Univ.Prague
France: France: IPHC Strasbourg
Hungaria:Hungaria:KFKI BudapestBudapest Univ.
Norway:Norway:Univ. Bergen
Russia:Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. PetersburgKurchatov Inst., MoscowLHEP, JINR DubnaLIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP MSU, Moscow St. Petersburg P. Univ.
Ukraine:Ukraine: T. Shevchenko Univ. KievKiev Inst. Nucl. Research
Germany: Germany: Frankfurt Univ. IKFFrankfurt Univ. FIAS GSI Darmstadt Giessen Univ.Heidelberg Univ. P.I.Heidelberg Univ. KIP Heidelberg Univ. ZITIHZ Dresden-RossendorfMünster Univ. Tübingen Univ. Wuppertal Univ.
Korea:Korea:Korea Univ. SeoulPusan Nat. Univ.
RomaniaRomania: : NIPNE BucharestUniv. Bucharest
India:India:Aligarh Muslim Univ.Panjab Univ. Rajasthan Univ.Univ. of Jammu Univ. of KashmirUniv. of CalcuttaB.H. Univ. VaranasiVECC KolkataSAHA KolkataIOP BhubaneswarIIT KharagpurGauhati Univ.
Poland:Poland:AGH Krakow Jag. Univ. KrakowSilesia Univ. KatowiceWarsaw Univ.
The CBM Collaboration: 55 institutions, 450 members
15st CBM Collaboration Meeting, April 12-16, 2010, GSI Darmstadt
Highest net-baryon densities at FAIR
• 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
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Ra
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