Transcript Heavy-Flavor related TOF upgrade in STAR  Identified hadron spectra

Heavy-Flavor related TOF upgrade in STAR
 Identified hadron spectra
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freeze-out dynamics
hadronization mechanism
Energy loss (color-charge/flavor)
Heavy-flavor rheology
 Identified particle correlations
 Chemical and kinetic properties of in-medium jet
associated spectra
 Fluctuations and correlations
 Lepton program
 In-medium vector meson properties
 Heavy flavor
 Baseline detector for future upgrades
 Heavy Flavor Tracker for electron background
 Muon Telescope Detector (dimuon)
Use TOF upgrade to connect past, present and future measurements
November 2007, LBL Heavy-flavor workshop
Zhangbu Xu, BNL
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The real ones
One DAQ1000 sector
5 TOF trays (total of 120 trays)
One MTD tray
Milestone:
Installed 10/23/2007
November 2007, LBL Heavy-flavor workshop
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Run7: DAQ1000+TOF location
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TOF
MTD
East 4 O’clock
Sector 16 (CTB76-80)
November 2007, LBL Heavy-flavor workshop
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Experimental and Theoretical Challenges
in the Search for the Quark Gluon Plasma
The STAR Collaboration’s Critical Assessment
of the Evidence from RHIC Collisions,
Nucl. Phys. A 757 (2005) 102
Strong evidences pointing to a “dense, opaque,
non-viscous, pre-hadronic liquid state of matter
not anticipated before RHIC”
Study the properties of this matter.
What are the critical needs from future
Experiments (STAR White paper)?
November 2007, LBL Heavy-flavor workshop
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Critical needs from future experiments
Near Term
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v2 scaling for coalescence
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PID spectra
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jet quenching as
parton energy loss
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energy dependence
testing model prediction

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Heavy flavor yields and
flow: color screening and
partonic ollectivity.
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
In-medium jet
Fluctuations and correlations
Lepton program


Thermometers: dilepton,
photon

heavy quarkonium species.

jet fragments tagged by a
hard direct photon, a heavy
flavor

elliptic flow in U+U
collisions.

LHC and GSI energies

fundamental QCD
symmetries
freeze-outs
hadronization
PID correlations



Long Term
TOF
In-medium Vector Meson
Heavy Flavor
Baseline detector for
future upgrades
forward jet correlation:
CGC
Near/Long Term: STAR white paper Nucl. Phys. A 757 (2005) 102
November 2007, LBL Heavy-flavor workshop
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Hadron identification:
STAR Collaboration, nucl-ex/0506026
Time Projection Chamber: 45 padrow, 2 meters (radius), s(dE/dx)8%, -1<<1
Multi-gap Resistive Plate Chamber TOFr: 1 tray (~1/200), s(t)=85ps
November 2007, LBL Heavy-flavor workshop
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What is TOF in STAR
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1. Open Charm measurements
with TOF (now and future)
p K p pT range (0.2<pT<3 GeV/c)
>80% efficient
2. J/y yields and spectra with TOF
||<0.9
f=2p
3. J/y At high-pt related to TOF
US-China Collaboration project
China: MRPC
US: electronics
November 2007, LBL Heavy-flavor workshop
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QCD Phase Diagram
A thermodynamic state is specified by a set of values of all
the thermodynamic parameters necessary for the description
of the system. --- statistical mechanics by K. Huang
Temperature (T), chemical potential (m), pressure(P) …
November 2007, LBL Heavy-flavor workshop
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Chemical/thermal Equilibrium
at certain stage of the evolution
2.
At the predicted QCD
phase boundary
3.
persistent from SPS to RHIC
4.
Below the phase boundary at
AGS and SIS
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What can TOF bring?
Particle
pT range (GeV/c)
TPC+TOF/TPC
K*0
0-1
2.0
K*0
1-2
1.85
K*0
2-3
1.74
K*0
3-5
1.39
f
0-2
5.0
f
2-5
3.42
L*
0-1.6
11.4
D0
0-5
4.6
 pKp pT range (1<pT<3 GeV/c)
>80% efficient
 W efficiency x8
 Resonances x2--10
November 2007, LBL Heavy-flavor workshop
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Open Charm
Mc,b 1.5 GeV>>Tc, LQCD, Muds
M/E>>0
1. Production at initial impact
2. Thermalization
 Full TOF improves (x5) charm hadronic reconstruction
 Charm semi-leptonic decay (c100mm)
 Cross section and spectra (prototype TOF) in p+p, d+Au Published
Phys. Rev. Lett. 94 (2005) 062301
November 2007, LBL Heavy-flavor workshop
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Electron Identification
TPC dE/dx: large hadron background
EMC: pT>~2.0 GeV/c
A prototype TOF tray (TOFr)
|1/β-1|<0.03
Not able to do without TOF!
Nucl-ex/0505026, M. Shao et al.
X. Dong PHD Thesis (USTC 2005)
November 2007, LBL Heavy-flavor workshop
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Prototype TOF related Charm Results
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Total Cross Section scales approximately with Nbin
Much larger than NLO pQCD (x5) but within syst.
Charm produced at initial impact,
sensitive to the early evolution/thermalization
Large errors, need improvement
November 2007, LBL Heavy-flavor workshop
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Low pT m for charm cross section
0.16<pT (m)<0.26 GeV/c
Sensitive to only total cross section
November 2007, LBL Heavy-flavor workshop
Y.F. Zhang, C. Zhong at QM06
H.D. Liu et al. nucl-ex/0601030
PLB 639 (2006) 441
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Identify m at low pT
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dE/dx + TOF PID
DCA rejects decay products (K/p)
Primordial background (~5%)
m+m- simulated to be ~2%
November 2007, LBL Heavy-flavor workshop
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Leptons from charm semileptonic decay
PRL98(2007)192301
1. Electrons in p+p and d+Au:
TOF HAD Very low statistics,
EMC large syst. error at low-pt
low-material run8—9 important
2. Total cross section:
D0->Kp (only in d+Au)
muon at low-pt (no statistics in p+p or d+Au)
3. Discrepancy between STAR/PHENIX (x2)
November 2007, LBL Heavy-flavor workshop
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Charm flow pattern
 High-pt quenched
 Spectra softening
<pT> (GeV/c)
d+Au: 1.18 0.02  0.10
minbias Au+Au: 0.92  0.06
Central Au+Au: 0.95  0.04
 Other hadrons have harder
spectra in AA due to flow
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Models:
R. Rapp et al. JPG 32(2006) S351
I. Vitev et al. hep-ph/0611109
D. Teaney et al. PRC71(2005) 064904
November 2007, LBL Heavy-flavor workshop
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Jet Quenching at RHIC
 One of the Major discoveries at RHIC
•How coalescence works?
•Vacuum fragmentation at pT>6 GeV/c?
•How jet energy dissipates in the medium
November 2007, LBL Heavy-flavor workshop
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“Color-charge”/flavor dependence
Wicks nucl-th/0512076
XN Wang PRC98
 dE/dx(g) ~=9/4 dE/dx(uds)
pbar, p vs p
 dE/dx(c/b)<dE/dx(uds)
November 2007, LBL Heavy-flavor workshop
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Identified high pT spectra
Log10(p)
 TOF covers 0.2<pT<5 GeV/c
 dE/dx at relativistic rise extends
PID beyond pT of 10 GeV/c
 dE/dx calibration matters!!!
November 2007, LBL Heavy-flavor workshop
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Jet Associated Spectra/Correlations
Leading
hadrons
Medium
Jet dissipates energy
Jet deflection
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Away-side spectra approaching the bulk
Chemically and thermally?
Need PID 1<pT<4 GeV/c
Not able to do without FULL TOF
Heavy-flavor related correlations
November 2007, LBL Heavy-flavor workshop
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What is TOF in STAR
1. Open Charm measurements
with TOF (now and future)
2. J/y spectra and flow with TOF
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p K p pT range (0.2<pT<3 GeV/c)
>80% efficient
||<0.9
f=2p
3. J/y At high-pt related to TOF
November 2007, LBL Heavy-flavor workshop
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J/y
 Thermalization & Color DOF
 Test Color Screen
 Coalescence of charm quarks
 v2
STAR J/y
PHENIX Acceptance:
||<0.35, f=2*p/2
STAR TOF-Upgrade Acceptance: ||<0.9, f=2*p
pT (e)>1.5 GeV/c
J/y yields from 1 billion minbias Au+Au events:
43.8x10-9/0.040x109*292*0.5*1.8*0.5= 144,000
sJ/y
spp N Nbin e y RAA
November 2007, LBL Heavy-flavor workshop
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What is TOF in STAR
1. Open Charm measurements
with TOF (now and future)
2. J/y spectra and flow with TOF
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p K p pT range (0.2<pT<3 GeV/c)
>80% efficient
||<0.9
f=2p
3. J/y At high-pt related to TOF
November 2007, LBL Heavy-flavor workshop
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High-pT J/
Zebo Tang, DNP07
PHENIX
run5
STAR Preliminary
run5 p+p, pT>5 GeV/c
1. Lots (x10) statistics
2. EMC high-tower trigger too high rate
3. EMC low-efficiency at low-pt,
dE/dx large background
4. EMC+TOF trigger:
enhance PID with reduced rate
5. SLOW TPC (not only TPX)
November 2007, LBL Heavy-flavor workshop
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Production puzzle
depending on production mechanism, the probe will be different:
charm quark, Bottom quark, direct quarkania, gluon
 In e+e- (BELLE), 60%
of J/y has associated charm pair
 On recent puzzles in the
production of heavy quarkonia.
B.L. Ioffe, D.E. Kharzeev
Phys.Rev.D69:014016,2004
 NLO (no in PYTHIA) is dominant?
 Dominant from B decay in
PYTHIA
 COM
November 2007, LBL Heavy-flavor workshop
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Bottom Spectrum from pQCD
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QCD predictions for charm and
bottom production at RHIC.
Matteo Cacciari, Paolo Nason,
Ramona Vogt
Published in
Phys.Rev.Lett.95:122001,2005.
e-Print: hep-ph/0502203
B Meson Upper curve taken
November 2007, LBL Heavy-flavor workshop
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BJ/ kinematics
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Measurements of inclusive B --> psi
production.
By CLEO Collaboration (S. Anderson
et al.). 2002. 5pp.
Phys.Rev.Lett.89:282001,2002
All we need is the kinematics of
BJ/ decay at rest.
Branching Ratio of B->J/Psi is 1.12%
from measurement
November 2007, LBL Heavy-flavor workshop
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PHENIX J/ in run5 p+p
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J/psi Production in p+p Collisions at
sqrt(s) = 200 GeV
Preprint: hep-ex/0611020
Published: Phys.Rev.Lett.98:232002,2007
Invariant cross section:
4.2/(1+pT2/16.6)6
VERY Large uncertainties at high-pt
November 2007, LBL Heavy-flavor workshop
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(BJ/)/(inclusive J/)
CDF both measured, pQCD/PHENIX
November 2007, LBL Heavy-flavor workshop
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Is J/ oversubscribed from Be?
pQCD Beauty production is on the low side
November 2007, LBL Heavy-flavor workshop
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STAR projection for QM08
 Red: run5 p+p
sample L ~=600(nb)
ET>3.5 GeV
 Pink: run6 p+p
sample L ~=2(pb)-1
ET>5.3 GeV
 Higher p+p equivalent
luminosity in Cu+Cu
and Au+Au (run5, run7)
November 2007, LBL Heavy-flavor workshop
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(BJ/)/(inclusive J/) from CDF
BJ/ displaced vertex
What can RHIC do?
CDF Collaboration (D. Acosta et al.), Phys.Rev.D71:032001,2005.
e-Print: hep-ex/0412071
November 2007, LBL Heavy-flavor workshop
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Baseline Detector for other upgrades
 TOF provides 2p and ||<0.9 coverage
 Future upgrades will benefit from or enhance the
capability of this detector
 .e.g. Heavy Flavor Tracker (HFT), Muon Telescope
Detector (MTD) and TOF can be a powerful device for
dilepton and heavy flavor programs
November 2007, LBL Heavy-flavor workshop
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Publications from STAR MRPC TOF Prototype
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Energy dependence of PID spectra at high-pt in Au+Au collisions (62 and 200 GeV)
published in Phys. Lett. B 655 (2007) 104
nucl-ex/0703040 (PLB);
Mass, quark-number, and sqrt(sNN) dependence of the second and
fourth flow harmonics in ultra-relativistic nucleus-nucleus collisions
Published in Phys. Rev. C 75 (2007) 54906
nucl-ex/0701010
Charm Cross section and spectra in p+p, d+Au;
Published Phys. Rev. Lett. 94 (2005) 062301; Phys. Lett. B 639 (2006) 441
Color-factor dependence of energy loss
Published Phys. Rev. Lett. 97 (2006) 152301;
nucl-ex/0609021
PID Cronin Effect in d+Au,
published in Phys. Lett. B 616 (2005) 8; Phys. Lett. B 637(2006)161
Charm yields, flow and Energy loss in Au+Au
SQM06, QM04, QM05, QM06 talks, 2 PHD theses (Xin Dong, Yifei Zhang)
p K p nucleus spectra for bulk/coalescence study in Au+Au and Cu+Cu
SQM04, QM05, QM06, SQM07 talks, two PHD theses (Lijuan Ruan, Haidong Liu)
8 NIMA publications:

Nucl.Instrum.Meth.A538:243-248,2005
Nucl.Instrum.Meth.A533:60-64,2004
Nucl.Instrum.Meth.A492:344-350,2002
Nucl.Instrum.Meth.A508:181-184,2003
Nucl.Instrum.Meth.A478:176-179,2002
Nucl.Instrum.Meth.A538:425-430,2005
Nucl.Instrum.Meth.A537:698-702,2005
Nucl.Instrum.Meth.A558:419-429,2006
2 PHD Thesis (Ming Shao, Yongjie Sun); 5 other Journal publications
More to come from prototype TOFr
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Imagine what we can accomplish with Full TOF
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November 2007, LBL Heavy-flavor workshop
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Conclusions
Near Term
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v2 scaling for coalescence

PID spectra



jet quenching as
parton energy loss


energy dependence
testing model prediction


Heavy flavor yields and
flow: color screening and
partonic ollectivity.


In-medium jet
Fluctuations and correlations
Lepton program


Thermometers: dilepton,
photon

heavy quarkonium species.

jet fragments tagged by a
hard direct photon, a heavy
flavor

elliptic flow in U+U
collisions.

LHC and GSI energies

fundamental QCD
symmetries
freeze-outs
hadronization
PID correlations



Long Term
TOF+future upgrades
In-medium Vector Meson
Heavy Flavor
Baseline detector for
future upgrades
forward jet correlation:
CGC
Near/Long Term: STAR white paper Nucl. Phys. A 757 (2005) 102
November 2007, LBL Heavy-flavor workshop
Zhangbu Xu, BNL
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HFT rejects gamma conversion

Background:   e+e-

HFT discriminates background

Need low mass detector

Statistics comparable to NA60

Charm background
Detectors
w
f
TPC+TOF+HFT
20K
6K
November 2007, LBL Heavy-flavor workshop
Zhangbu Xu, BNL
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Muon Identification in STAR
 Low pT muon
 Charm Cross sections
 Low mass dilepton
 Detectors required: TOF+TPC+HFT
Muon Detector outside STAR magnets
 High pT muon
 Heavy Flavor leptonic decay
 Quarkonia
 IMR dilepton, DY
 e-m correlation ccbar background
 Possible higher pT (~10 GeV/c) hadron trigger
November 2007, LBL Heavy-flavor workshop
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HIJING event simulation
100 HIJING central events:
2 Events with >=2 hits (online)
3 out of 840 tracks matched (pT>2 GeV/c)
TPC rdE/dx+TOF reject ~5 hadrons
Hadron rejection: 103
Pt (GeV)
November 2007, LBL Heavy-flavor workshop
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R&D Detector Requirements
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Large Coverage (cost-effective)
Time (< ns)
Spatial resolution (<cm)
Some dE/dx capability
Tracking capability? (Nikolai)
Possible candidates:
 Scintillators
 RPC
 MRPC (large pad, two-end readout)
 Proportional Wire Chamber
 Straw Station?
 Some Combinations of above or others?
November 2007, LBL Heavy-flavor workshop
Zhangbu Xu, BNL
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Muon Telescope Detector
MTD
Two spare CTB scintillators
in for run6 p+p
background study, Detector R&D
November 2007, LBL Heavy-flavor workshop
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 Thanks to STAR collaborators:
Xin Dong(USTC), Lijuan Ruan(LBL)(TOF e/h dAu, rdE/dx AuAu)
Haibin Zhang(BNL) (resonances, charm)
Haidong Liu(USTC), Yifei Zhang(USTC), Ming Shao (USTC)
Chen Zhong(SIAP) (TOF e/m/h)
Pawan Netrakanti, Bedanga Mohanty (VECC) (rdE/dx pp/dAu)
Johan Gonzalez(UCLA) (d+Au), Gang Wang (Kent) (ZDC)
Guoji Lin(Yale) (MTD R&D)
Patricia Fachini (BNL), Aihong Tang (BNL), Olga
Barannikova(UIC), Fuqiang Wang(Purdue), Nu Xu (LBL)
November 2007, LBL Heavy-flavor workshop
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STAR MRPC TOF Publications
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Charm Cross section and spectra in p+p, d+Au;
Published Phys. Rev. Lett. 94 (2005) 062301
Charm Energy Loss in Au+Au
QM04, QM05 talks, two PHD theses (1+1)
PID Cronin Effect in d+Au,
published in Phys. Lett. B 616 (2005) 8
p K p spectra for bulk/coalescence study in Au+Au and Cu+Cu
SQM04, QM05 talks, two PHD theses (1+1)
8 NIMA publications:

Nucl.Instrum.Meth.A538:243-248,2005
Nucl.Instrum.Meth.A533:60-64,2004
Nucl.Instrum.Meth.A492:344-350,2002
Nucl.Instrum.Meth.A508:181-184,2003
Nucl.Instrum.Meth.A478:176-179,2002
Nucl.Instrum.Meth.A538:425-430,2005
Nucl.Instrum.Meth.A537:698-702,2005
nucl-ex/0505026 (submitted)
One PHD Thesis
More to come from prototype TOFr

Imagine what we can accomplish with Full TOF



November 2007, LBL Heavy-flavor workshop
Zhangbu Xu, BNL
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Charm and electron RAA and v2
 Identified D0 consistent with binary scaling at low pT
 Non-photonic electrons arise primarily from c and b
 Large charm suppression and v2 at intermediate pT
November 2007, LBL Heavy-flavor workshop
Zhangbu Xu, BNL
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Charm Spectrum Measurement
• Au + Au, 50M central events
• D0  K + p
• Stat. uncertainties small
D0 Reconstruction Efficiency
• D0  K + p
• Efficiency small at low
momentum: Decay length cut
•We can subtract DDbar 
•Alternative Approach:
reject electrons event-by-event
(in progress)
•HFT resolution <10mm
> 200mm
e+e-
• Increases with pT and then
saturates
• ALICE-type pixel layers:
Efficiency drops by factor 8!
 Need low mass detector !
14
November 2007, LBL Heavy-flavor workshop
RHIC II workshop, BNL, Apr 29 - 30, 2005
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Muon ID at low pT
1. Charm Cross sections
2. Low mass dilepton
p
e
m
m less Dalitz decay and  conversion (<x10),
Decays from p,K rejected by HFT DCA
Dilepton mass: 0.2<m<0.6 GeV
November 2007, LBL Heavy-flavor workshop
STAR Preliminary:
0.15<pT<0.25 GeV/c, DCA<3cm
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RAA of non-photonic electrons
Wicks nucl-th/0512076
Evidence of large heavy quark energy loss!
Suppression of proton, pion, and heavy flavor ~0.2
No color-charge, flavor dependence?
Nature doesn’t like accidences!
November 2007, LBL Heavy-flavor workshop
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