STAR Physics Program
- Spin Structure of Proton
- Properties of QCD Matter at Extreme Conditions
- QCD Phase Structure
Nu Xu
(1) Nuclear
Science Division, Lawrence Berkeley National Laboratory
Berkeley, USA
(2) College of Physical Science and Technology, Central China Normal University
Wuhan, China
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
1/15
STAR Experiment
STAR Experiment at RHIC
( http://www.star.bnl.gov/ )
Fundamental science: particle physics, nuclear
physics, astrophysics, cosmology, …
State of art technology: detector R&D, simulations,
IT, computing, mass/fast data managing, …
- 550 scientists
- 55 institutes
- 13 countries
- 130 PhD thesis since 2001
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
2/15
STAR Physics Focus
1) At 200 GeV top energy
- Study medium properties, EoS
- pQCD in hot and dense medium
2) RHIC beam energy scan (BES)
- Search for the QCD critical point
- Chiral symmetry restoration
Forward program
- Study low-x properties, initial condition,
search for CGC
- Study elastic and inelastic processes in
pp2pp
Polarized p+p program
- Study proton intrinsic properties
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
3/15
STAR Detectors Fast and Full azimuthal particle identification
TPC
TOF
EMC+EEMC+FMS
(-1 ≤  ≤ 4)
DAQ1000
HFT
2013
FGT
BNL PAC, 21 - 22, 2010
2011
MTD 2013
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
4/15
Particle Identification at STAR
TPC
ToF
TPC
STAR TPC
K
p
d
π
e, μ
STAR ToF
Log10(p)
STAR MTD
STAR HFT
STAR EMC
Neutral particles Strange
hyperons
Jets
Heavy Quark
Hadrons
Multiple-fold correlations among the identified particles!
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
5/15
TOF Performance (2010)
√sNN = 39 GeV Au + Au Collisions
TPC
TPC+ToF
Beam Energy
Timing Resolution
200 (GeV)
85 (ps)
62.4 (GeV)
90 (ps)
39 (GeV)
85 (ps)
11.5 & 7.7 (GeV)
~ 80 (ps)
Nu Xu
Remarks
At 39 GeV, using a new calibration
scheme without information of start
time from VPD, 87 ps of timing
resolution has been achieved.
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
6/15
STAR Upgrade Timeline*
Upgrade
Completion
Key Physics Measurements
FMS
Completed 2008
(a) Trans. Asymmetry at forward-y
(b) CGC
TPC DAQ1000
Completed 2009
Minimal dead time, large data set
MRPC TOF
Completed 2010
Fast PID in full azimuthal acceptance
Forward GEM
Tracker
Summer 2011
Ready for Run 12
Forward-y W± for flavor separated
quark polarization
Heavy Flavor Tracker
Summer 2013
Ready for Run 14
(a) Precision hadronic ID for charm
and Bottom hadrons
(b) Charm and Bottom hadron energy
loss and flow
Muon Telescope
Detector
Summer 2013
Ready for Run 14
(a) High pT muon trigger
(b) Quarkonia states
pp2pp’
Summer 2014
Ready for Run 15
*Upgrades - Funding driven schedules
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
7/15
Forward GEM Tracker (2011)
HFT
FGT
1) FGT: RHIC CE project
2) Six light-weight triple-GEM disks
3) New mechanical support structure
4) Planned installation: Summer 2011
1) Full charge-sign discrimination at highpT
2) Design polarization performance of 70%
to collect at least 300pb-1
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
8/15
Heavy Flavor Tracker (2014)
SSD
HFT
IST
PXL
FGT
1) Identify heavy flavor hadron directly
2) Precision measurement HF hadron
energy loss and collectivity
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
9/15
HFT: Charm Hadron v2 and RAA
- 200 GeV Au+Au m.b.
collisions (500M events).
- Charm hadron collectivity 
drag/diffusion constants 
- 200 GeV Au+Au m.b.
collisions (|y|<0.5 500M events)
- Medium properties!
- Light quark thermalization!
- Energy loss mechanism!
- QCD in dense medium!
Nu Xu
- Charm hadron RAA 
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
10/15
Muon Telescope Detector (2013)
beam pipe
TPC
TOF
EMC
magnet
MTD
Muon Telescope Detector (MTD) at STAR:
1) MRPC technology; με ~ 45%; cover ~60% azimuthally and |y| < 0.25
2) TPC+TOF+MTD: muon/hadron enhancement factor ~ 102-3
3) For high pT muon trigger, heavy quarkonia, light vector mesons, BJ/+X
4) China-India-STAR collaboration: a proposal sub. to BNL 02/2010.
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
11/15
Summary
STAR QCD physics program for next decade:
Spin Physics:
(cold nucleon)
- 200 GeV: Δg inclusive and di-jets, γ-jet
- 500 GeV: sea quark helicity distributions
- 200/500 GeV: transverse spin phenomena
Low-x Physics:
(cold nucleus)
- Study gluon-rich phenomena at RHIC
- Color glass condensate
Heavy Ion Physics:
(hot nuclear matter)
- Thermalization at √sNN = 200 GeV
- QCD phase boundary and critical point
- In medium properties
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
12/15
Decadal Plan see Carl’s talk
Decadal Plan
C. Gargliardi
Spin
Heavy Ion
Upgrade
B. Surrow
J. Dunlop
F. Videbaek
Charge for new decadal plans for
STAR and PHENIX
by Steve Vigdor, Dec. 17, 2009
http://drupal.star.bnl.gov/STAR/event/2009/12/10/star-management-meeting
due date: Oct. 1, 2010
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
13/15
eRHIC Design
eRHIC detector
2 SRF linac
1 -> 5 GeV per pass
4 (6) passes
RHIC: 325 GeV p
or 130 GeV/u Au with
DX magnets removed
eSTAR
S. Vigdor:
2010 Operation review
STAR Experiment
MRPC ToF Barrel
MTD
EMC Barrel
EMC End Cap
ALICE Technology
FMS
BBC
FHC
FPD
TPC
pp2pp’
pp2pp’
PMD
trigger
DAQ1000
HLT
Nu Xu
computing
COMPLETE
HFT
FGT
Ongoing
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
R&D
15/15
有客之远方来， 不亦乐乎！
Nu Xu
STAR Regional Meeting, ShanDong University, Jinan, , 22 – 23, October, 2010
16/15