Nu Xu 1/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
QCD in the Twenty-First Century
(1) Higgs (-like) Particle – - Origin of Mass, QCD dof
- Standard Model The Theory
(2) QCD Emerging Properties –- Confinement, χC symmetry- QCD Phase Structure
- Nucleon helicity structure - … - Non-linear QCD at small-x - …
Emergent properties with QCD degrees of
freedom!
Nu Xu 2/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
High-Energy Nuclear Collisionsand QCD Phase Structure
Nu Xu(1,2)
(1) College of Physical Science & Technology, Central China Normal University, Wuhan, 430079, China (2) Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Nu Xu 3/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
2 TE RHIC, SPS, FAIR
3
3 Phase boundaryRHIC, FAIR, NICA
Exploring the QCD Phase Structure
1
1 Tini, TC
LHC, RHIC
2Pa
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ic M
atte
r
Had
roni
c M
atte
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Nu Xu 4/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
QCD ThermodynamicsSB Ideal GasRHIC
LHC
1) At μB = 0: cross over transition, 150 < Tc < 200 MeV
2) The SB ideal gas limit: T/Tc ~ 107
3) Tini (LHC) ~ 2-3*Tini (RHIC)
4) Thermodynamic evolutions are similar for RHIC and LHC
Zoltan Fodor, Lattice 2007
Nu Xu 5/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Jets at SPS, RHIC and LHC
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1) Stronger suppression at higher collision energies 2) RAA ~ 0.5 for charged hadrons at high pT (~100 GeV/c)
in central Pb+Pb central collisions
Nuclear modification factor:
€
R AA =dNAA /dp T
⟨TAA⟩dσ pp /dp T
⟨TAA⟩=⟨ncoll ⟩σ inel
NN
RCP =dNAA /dp T /ncoll centdNAA /dp T /ncoll per
Nu Xu 6/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Medium Effects:Quarkonia
key words: thermometer, deconfinement, Debye screen, regeneration (coalescence)
Nu Xu 7/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
J/ψ Suppression or Enhancement
mid-rapidity forward-rapidity
1) Due to large charm production cross section at LHC and coalescence process, the J/ψ RAA increased in mid-rapidity at central collisions. More such increase is expected in √sNN = 5.5 TeV Pb+Pb collisions.
2) Both suppression: “Debye Screening” and the recent observed increase: “Coalescence”, demonstrating the sQGP medium effect.
Model Comparisonsmid-rapidity forward-rapidity
1) Models predict yield RAA well.2) To indentify the production
mechanism and study the properties of the medium: shadowing, collectivity, coalescence, etc, study:
More see Pengfei’s talk.
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R AA(pT2 ) = pT
2 AA/ pT
2 pp
Upsilon Productions
1) Temperature measurement?2) Systematic study transverse momentum
dependence of quarkonia productions in high-energy nuclear collisions:
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R AA(N) = NAA / N pp
RAA(pT) =N(pT)AA /N(pT)
pp
RAA(pT2 ) = pT
2 AA/ pT
2 pp
Nu Xu 10/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Medium Effects:Collectivity
key words: partonic collectivity, thermalization, perfect liquid
1) Collectivity increase as collision energy
2) √sNN > 39 GeV, partonic dominant √sNN ≤ 11 GeV, hadronic dominant
STAR data: arXiv:1206.5528ALICE data: Phys. Rev. Lett. 105, 252302 (2010)
Collectivity vs. Collision Energy
Nu Xu 12/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Collectivity ~ Collision EnergyALICE: PRL105, 252302(10); arXiv:1208.1974STAR: PRC66, 034904(02); PRC72, 014904(05); PHENIX: PRL98, 162301(07); PHOBOS: PRL98, 242302 (07) CERES: NPA698, 253c(02); E877: NPA638, 3c(98); E895: PRL83, 1295(99).
STAR Preliminary
Nu Xu 13/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Di-electrons: √sNN Dependence
1) Di-lepton: penetrating-bulk probe2) LMR: no significant energy dependence in enhancement3) Future: focus in 1 < mll < 3 GeV/c2, to
- Measure correlated charm contributions- Extract direct radiation information
Nu Xu 14/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Light hadron collectivity: partonic + hadronic
(s, c) hadron collectivity: partonic!
Di-leptons (m > 1 GeV) collectivity: 1) partonic2) direct radiation
√sNN = 200 GeV Au + Au Collisions
Future: Partonic Collectivity, Direct Radiation
Nu Xu 15/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
sQGP and QCD Phase Structure
sQGP formed at μB ~ 0: - Collectivity: NCQ scaling in v2, … - Jet-quenching, Quarkonia, γ, …
RHIC BES-I Program: - Partonic dominant: √sNN > 39 GeV (μB ≤ 100 MeV) - Hadronic dominant: √sNN ≤ 11.5 GeV (μB ≥ 300 MeV)
What is the structure of the QCD phase diagram? - phase boundary? - QCD critical point?
Observations:(1) Azimuthally HBT 1st order phase transition
(2) Directed flow v1
1st order phase transition
(3) Dynamical correlations partonic vs. hadronic dof
(4) v2 - NCQ scaling partonic vs. hadronic dof
(5) Fluctuations Critical point, correl. length
- http://drupal.star.bnl.gov/STAR/starnotes/public/sn0493- arXiv:1007.2613
Nu Xu 16/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Medium Effects:Critical Point
key words: QGP phase, hadronic phase, 1st order phase boundary, critical end point, correlation length, critical
slowing down...
Nu Xu 17/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Higher Moments
1) High moments for conserved quantum numbers: Q, S, B, in high-energy nuclear collisions
2) Sensitive to critical point (ξ correlation length):
3) Direct comparison with Lattice results:
4) Extract susceptibilities and freeze-out temperature. An independent/important test on thermal equilibrium in heavy ion collisions.
- A. Bazavov et al. 1208.1220 (NLOTE)- STAR Experiment: PRL105, 22303(2010)- M. Stephanov: PRL102, 032301(2009)- R.V. Gavai and S. Gupta, PLB696, 459(2011)- S. Gupta, et al., Science, 332, 1525(2011)- F. Karsch et al, PLB695, 136(2011)- M.Cheng et al, PRD79, 074505(2009)- Y. Hatta, et al, PRL91, 102003(2003)
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dN( )2 ≈ ξ 2, δN( )
3 ≈ ξ 4.5, δN( )4 ≈ ξ 7
S *σ ≈ χ B3
χ B2 , κ *σ 2 ≈ χ B
4
χ B2
M. Cheng et al, PRD79, 074505(2009)
R. Gavai and S. Gupta, QM2012
Nu Xu 18/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Higher Moment: Net-charge
STAR Preliminary
- PHENIX: E. O’Brien, QM2012- STAR: D. McDonald, QM2012 - HRG Model: K. Redlich et al, private communications, 2011
Nu Xu 19/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
STAR net-proton results: 1) All data show deviations below
Poisson beyond statistical and systematic errors in the 0-5% most central collisions for κσ2 and Sσ at all energies.
2) UrQMD model show monotonic behavior
3) Higher statistics needed for collisions at √sNN < 20 GeV
Net-proton Higher Moments
STAR Preliminary
STAR: X.F. Luo, QM2012
Nu Xu 20/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
Summary and Outlook1) Heavy flavor:
(a) NMF for HF jets and hadrons extract transport properties and understand energy loss
mechanism (b) Collectivity of HF hadrons thermalization of the medium
2) Di-lepton: pT, v2, RAA, polarization temperature and collectivity of the partonic medium
3) RHIC BES-II/NICA/FAIR at √sNN < 20 GeV exploring QCD phase diagram, search for the possible critical point, quarkyonic matter
4) small-x (forward-y) physics exploring the structure of cold nuclear matter, dynamical evolution from the CNM to sQGP
LHC/RHIC provides unique opportunities for exploring matter with QCD degrees of freedom!
Nu Xu 21/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
2 TE RHIC, SPS
3
3 Large μB
NICA, FAIR, CSR
研究 量子色动力学 (QCD) 相结构
1
1 Tini, TC
LHC, RHIC
2Pa
rton
ic M
atte
r
Had
roni
c M
atte
r
LHC+RHICsQGP properties
√sNN ~ few TeV
RHIC BES-IIQCD phase
structure and critical point √sNN ≤ 20 GeV
NICA/FAIRQCD phase structure
√sNN ≤ 12 GeV
Future eRHICCold nuclear
matter properties
e + ion collisions
Emergent properties of QCD matter
Nu Xu 22/20 ”ATHIC2012“, Pusan, Korea, November 14 - 17, 2012
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