Quarkonium Production in Heavy Ion Collisions · 2012. 10. 19. · Quarkonia not produced in QGP but produced statistically at hadronization from available c c pairs 13 Coalescence

The Return of the Prodigal Son ?

Quarkonium Production in Heavy-Ion Collisions

Thomas S. Ullrich (BNL)International Workshop on Heavy Quarkonia 2008December 2-5, 2008Nara, Japan

The Return of the Prodigal Son Pompeo Batoni (1773)

The Phases of QCD

2

Quark Gluon PlasmaA state of matter without color confinement that exhibits collective effects

• Lattice says crossover at µB = 0 • Some discussion on methods to extract TC (175 ≤ TC/MeV ≤ 191)• Lattice suggest the transition becomes 1st order at µB above the

critical point (2nd order at the CP)

Nuclear

Matter

Color Flavor Locking Phase

QGP

Color

Superconductivity

Vacuum

Early Universe

Crossover

CriticalPoint

Hadron Gas

0 200 400 600 800 1000 1200 20001400 1600 18000

50

100

150

200

250

T (

Me

V)

µB (MeV)

CHEN06

KSTD02

The Phases of QCD

2

Quark Gluon PlasmaA state of matter without color confinement that exhibits collective effects

• Need experiments to explore the phase diagram of QCD• Heavy Ion Collisions at RHIC create conditions sufficient to “melt”

matter into a quark gluon plasma

Nuclear

Matter

Color Flavor Locking Phase

QGP

Color

Superconductivity

Vacuum

Early Universe

Crossover

CriticalPoint

Hadron Gas

0 200 400 600 800 1000 1200 20001400 1600 18000

50

100

150

200

250

T (

Me

V)

µB (MeV)

CHEN06

KSTD02

3

The Phase Transition in the Laboratory

time !0

QGP

pre

- e

qu

ilib

riu

m

Co

llisio

n

Thermal Freeze-Out (el. collisions cease)

Chemical Freeze-Out (inel. collisions cease)

Phase Transition/ Cross-Over

Hadron Gas

Tc Tch Tfo

3

The Phase Transition in the Laboratory

time !0

QGP

pre

- e

qu

ilib

riu

m

Co

llisio

n

Thermal Freeze-Out (el. collisions cease)

Chemical Freeze-Out (inel. collisions cease)

Phase Transition/ Cross-Over

Hadron Gas

Tc Tch Tfo

non-linear QCD, BK, Color Glass Condensate

pQCD (LO, NLO)

Non-perturbative QCD, Hydrodynamics

Hadronic Models(RQMD, AMP)

Statistical thermal models,Fragmentation Functions

• Gluon density in initial state?

• saturation phenomena

• initial state effects (shadowing, EMC)

• thermalization (how?)

• Hard Processes

• High-pt partons• Heavy Flavor• direct photons

• Collective Flow• Color screening• Jet quenching &

medium response• Chiral Symmetry

Restoration ⇒ mass shifts

• thermal radiation

• Particle formation

• Fragmentation• Recombination

/ Coalescense• Hadronic

absorption

• Particle ratios• Particle yields• Hadrochemistry• High-pT partons

fragment ⇒ jets

4

Bevalac-LBL and SIS-GSI fixed target max. 2.2 GeV

AGS-BNL fixed targetmax. 4.8 GeV

SPS-CERN fixed targetmax. 17.3 GeV

TEVATRON-FNAL (fixed target p-A)max. 38.7 GeV

RHIC-BNL collidermax. 200.0 GeV

LHC-CERN collidermax. 2760.0 GeV

BRAHMS, PHENIX, PHOBOS, STAR

ALICE, ATLAS, CMS

NA35/49, NA44, NA38/50/51, NA45, NA52, NA57, WA80/98, WA97, …

E864/941, E802/859/866/917, E814/877, E858/878, E810/891, E896, E910 …

1992Au-Au

1994Pb-Pb

2000Au-Au

2009?Pb-Pb

Energy Frontier HistoryNuclear FragmentationResonance ProductionStrangeness Near Threshold

Resonances DominateLarge Net Baryon DensityStrangeness Important

Charm Production Starts

Low Net Baryon DensityHard Parton Scattering, JetsBeauty Production

Z-jet ProductionMore of everything

Discoveries at RHIC

5

• Strong Elliptic Flow‣ Collective flow of created matter‣ Constituent quark number degrees

of freedom apparent in scaling laws of elliptic flow

• Jet Quenching‣ Energy loss of high-pT partons

traversing the hot and dense matter‣ Medium response: conical flow (?),

ridge

• “Black Body” Radiation‣ Thermalized hot matter emits EM

radiation ⇒ Ti = 300-600 MeV

• Particle Production through recombination/coalescence dominates over fragmentation at medium pT

Discoveries at RHIC

5

• Strong Elliptic Flow‣ Collective flow of created matter‣ Constituent quark number degrees

of freedom apparent in scaling laws of elliptic flow

• Jet Quenching‣ Energy loss of high-pT partons

traversing the hot and dense matter‣ Medium response: conical flow (?),

ridge

• “Black Body” Radiation‣ Thermalized hot matter emits EM

radiation ⇒ Ti = 300-600 MeV

• Particle Production through recombination/coalescence dominates over fragmentation at medium pT

⇐ these and comparisons to models led to the “perfect fluid” hypothesisParadigm shift: strongly coupled QGP = sQGP

dN

dϕ∝ 1 + 2v2 cos[2(ϕ− ψR)] + ...

v2 = 〈cos[2(ϕ− ψR)]〉

Elliptic Flow – Indicator for Early Thermalization

6

!

!-"R

"R

Reaction Plane

Initial spatial anisotropy

Final state anisotropy in momentum space

Interactions

Use a Fourier expansion to describe the angular dependence of the particle density

bbeam

!10 !5 0 5 10

!10

!5

0

5

10

x (fm)

y (

fm)

Au+Au at b=7 fm

Elliptic Flow – Indicator for Early Thermalization

6

!

!-"R

"R

Reaction Plane

!10 !5 0 5 10

!10

!5

0

5

10

x (fm)

y (

fm)

Au+Au at b=7 fmP. Kolb, J. Sollfrank, and U. HeinzAu+Au at b=7 fm

τ1 τ2 τ3 τ4

driving spatial anisotropy vanishes ⇒ self quenching v2 → sensitive to early interactions and pressure gradients

7

The Flow is ≈ Perfect Huge asymmetry found at RHIC

‣ massive effect in azimuthal distribution w.r.t reaction plane

“Fine structure” v2(pT) for different mass particles ‣ good agreement with ideal (zero

viscosity η, λ=0) hydrodynamics

‣ small η ⇒ large σ ⇒ strong coupling ⇒ “perfect liquid”

Conjectured quantum limit: ‣ Kovtun, Son, Starinets, PRL.94:111601,

motivated by AdS/CFT correspondence

2v2

Turns out RHIC is very close to this limit (factor ~2)

8

Probes of Dense Matter – Jet Tomography

8

Probes of Dense Matter – Jet Tomographyp+p Collision

8

Probes of Dense Matter – Jet TomographyAu+Au Collision

8


Induced Gluon Radiation: Multiple final-state gluon radiation off the produced hard parton induced by the traversed dense colored medium

Medium

EHard

Production

!=xE

!=(1-x)E

"!

"qT~µ

8


Induced Gluon Radiation: Multiple final-state gluon radiation off the produced hard parton induced by the traversed dense colored medium

Medium

EHard

Production

!=xE

!=(1-x)E

"!

"qT~µ

• Mean parton energy loss ∝ medium properties:‣ ΔEloss ~ ρgluon and ~ ΔL2

• Characterization of medium‣ transport coefficient‣ gluon density dNg/dy

‣ RHIC:‣ 〈q〉 ~ 13 GeV2/fm (model

dependent!)‣ dNg/dy ~ 1400

High-pT Suppression – Matter is OpaqueHow to Measure Suppression?

9

Nuclear Modification Factor:

Ncoll = 〈# of NN collision〉 in AA collision


9



Observations at RHIC:1. Photons are not suppressed

Expected! γ don’t interact with medium

Ncoll scaling works2. Hadrons are suppressed in

central collisions Huge: factor 5


9



Observations at RHIC:1. Photons are not suppressed

Expected! γ don’t interact with medium

Ncoll scaling works2. Hadrons are suppressed in

central collisions Huge: factor 5

3. Azimuthal correlation function shows ~complete absence of “away-side” jet

Unexpected: Heavy Quarks Suppressed and Flow

10

ωdI

dw

∣∣∣∣HEAVY

=ω dI

dw

∣∣LIGHT(

1 +(

mQ

EQ

)21θ2

)2

Q

Dead cone effect implies lower heavy quark energy loss in matter:

Dokshitzer and Kharzeev, PLB 519 (2001) 199.

• Substantial suppression on same level to that of light mesons

• Charm flows !• Describing suppression and flow is

difficult for models

Semileptonic decays: c,b→e X

(GeV/c)T

p0 2 4 6 8 10

AA

R

1

0.1

/dy = 1000gDVGL Rad dN

/fm 2= 10 GeVqBDMPS c+b

DGLV Rad+EL

van Hees Elastic

DGLV charm Rad+EL

Collisional dissociation

STAR Au+Au 0-5% (PRL98, 192301)PHENIX Au+Au 0-10% (PRL96,032301)

(e++e-)/2

Au+Au (central) !sNN=200 GeV

hadrons

Alan Dion, QM2008

Quarkonia: A Compelling Probe

11

Key Idea: Melting in the plasma (Matsui & Satz PLB 178 (86) 416)• Color (Debye) screening of static potential between heavy quarks• Suppression of states is determined by TC and their binding energy

Sequential disappearance of states:⇒ QCD thermometer ⇒ Properties of QGP !c(1P)

"(1S)

"(2S)

"(3S)J/#(1S)

#$(2S)

Tc


11

Reality Check:‣ Almost all we learned about the (s)QGP comes from the light quark sector‣ Little insight from quarkonia (yet)‣ Formation time is not short compared to plasma formation time (τ~ 0.45 fm)


Sequential disappearance of states:⇒ QCD thermometer ⇒ Properties of QGP !c(1P)

"(1S)

"(2S)

"(3S)J/#(1S)

#$(2S)

Tc


11

Reality Check:‣ Almost all we learned about the (s)QGP comes from the light quark sector‣ Little insight from quarkonia (yet)‣ Formation time is not short compared to plasma formation time (τ~ 0.45 fm)


Sequential disappearance of states:⇒ QCD thermometer ⇒ Properties of QGP

But then: Quarkonia suppression is the only signature of a deconfined state we have!

!c(1P)

"(1S)

"(2S)

"(3S)J/#(1S)

#$(2S)

Tc

What’s the Problem with Quarkonia in HI ?The initial assumption (hope) was:

• Detailed understanding of production mechanism not essential• Suppression of J/ψ(A, centrality, pT) does the job

12



12

Wrong



12

Wrong

1. Feed down • ψ’ and χc melt at low T• ψ’ / χc → J/ψ + X

• B → J/ψ + X (≥RHIC)• ⇒ Measure in pp, pA

Example:Study for SPS: Can explain J/ψ suppression with melting of ψ’,χc Right or wrong, it shows how importantthe χc measurement is!

F. Karsch, D. Kharzeev, H. Satz, hep-ph/0512239

... More Issues ...2. RegenerationStatistical coalescence:Quarkonia not produced in QGP but produced statistically at hadronizationfrom available c c pairs

13

Coalescence in QGP:Quarkonium can exist together with un-bound heavy quarks in QGP

Very sensitive to σc c

Understanding of detailed balance of J/ψ depletion and restoration is necessary

A. Andronic et al. NPA 789 (2007) 334

... More Issues ...2. RegenerationStatistical coalescence:Quarkonia not produced in QGP but produced statistically at hadronizationfrom available c c pairs

13

Coalescence in QGP:Quarkonium can exist together with un-bound heavy quarks in QGP

Very sensitive to σc c

Understanding of detailed balance of J/ψ depletion and restoration is necessary

... and More ...3. Cold Nuclear Matter (CNM) Effects

Initial state effects:

‣ pT broadening (Cronin)

‣ PDF modification (shadowing)

‣ Gluon saturation (initial)Final state effects

‣ Breakup cross section of cc in the nucleus

‣ Energy-loss (dE/dx)

4. Hot Matter EffectsCharm quark energy loss

‣ induced gluon bremsstrahlung

‣ collisional energy lossCo-mover absorption

‣ absorption by abundantly produced hadrons in final state

14

LHC |y|<1

RH

IC |y|<

1

10-4 10-3 10-2 10-1 10.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

RgP

b(x

)

x

EPS08EKS98HKN07EKPS

Q2=1.69 GeV2

Eskola, Paukkunen, Salgado,

arXiv:0802.0139 [hep-ph]

anti-shadowing E

MC

Ferm

i-M

otion

shadowing Shadowing|Antishadowing|EMC

N.B.: Measuring Suppression

15

CERN/SPS: NA50• S = J/ψ / Drell-Yan

+ direct measurement+ model independent+ DY A-scaling under control- statistics

CERN/SPS (NA60)• Glauber

χ2/ndf = 1.24

DYJ/ψ, ψ’DD

RHIC

!s = 200 GeV


15




χ2/ndf = 1.24

DYJ/ψ, ψ’DD


15




χ2/ndf = 1.24

DYJ/ψ, ψ’DD

BNL/RHIC• Cannot use DY (cc > DY)• Use:

+ statistics independent+ Glauber (Ncoll) under control- systematic uncertainties large for peripheral collisions

16

CERN/SPS: NA38/NA50/NA60Charmonium suppression at SPS energies (√s~29 GeV, √sNN~17 GeV)

• Studied since 1986 by NA38, NA50 and NA60 experiments• Large variety of nuclear beams‣ S-U at 200 GeV/nucleon (NA38)‣ Pb-Pb at 158 GeV/nucleon (NA50)‣ In-In at 158 GeV/nucleon (NA60)

• Proton beams used to collect reference data‣ p-A at 400/450 GeV (NA50)‣ p-A at 400/158 GeV (NA60)

hadronabsorber Muon

Other

NA10/38/50 spectrometer Muon trigger & tracking

magnetic field

Iron wall

2.5 T dipole magnet

Matching in coordinate and momentum space

targets

beam tracker

vertex tracker

p+A: Systematic Study of σabsJ/ψ

17

Revisiting measurementsfor y=0: Indication of energy dependence

see talk by H.Woehri’s later

σabsJ/ψ is essential to extract suppression in A+A collisions

Main assumptions used up to now: σabsJ/ψ energy independent

Surprise NA60 at Ebeam=158 GeV: σabs J/ψ = 7.1 ± 1.0 mb

NA50 at 400/450 GeV: σabs J/ψ = 4.2 ± 0.5 mb

!"#$%&''(

)* +* ,* -* .* /* 0*

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Anomalous J/ψ suppression at SPS

Using higher σabsJ/ψ does not change the qualitative picture

• S+U shows no anomalous suppression • In+In exhibits a smaller effect • Pb+Pb shows anomalous suppression in central events

〈# of Participants in Collision〉 ~ Centrality

P. Cortese/Hard Probes 2008NA60 Preliminary

Using new NA60 σabs

J/ψ results

450, 400 and 200 GeV results rescaled to 158 GeV!

〈Length Traversed〉 (fm)

19

Quarkonia Measurements at RHICPHENIX• Central Arms:‣ J/ψ→ e+e-, ψ’ → e+e-, χc → e+e-γ‣ |η|<0.35, Δφ=2⋅π/4, pe > 0.2 GeV/c

• Forward Arms:‣ J/ψ → µ+µ- ‣ 1.2<|η|<2.2, pµ > 1 GeV/c, Δφ = 2π‣ Trigger

19

Quarkonia Measurements at RHICPHENIX• Central Arms:‣ J/ψ→ e+e-, ψ’ → e+e-, χc → e+e-γ‣ |η|<0.35, Δφ=2⋅π/4, pe > 0.2 GeV/c

• Forward Arms:‣ J/ψ → µ+µ- ‣ 1.2<|η|<2.2, pµ > 1 GeV/c, Δφ = 2π‣ Trigger

STAR• Main Barrel‣ J/ψ→ e+e-, ϒ→ e+e-

‣ |η|<1, Δφ=2 π, pe > 0.2 GeV/c‣ Trigger for high-pT e

• Forward Meson Spectrometer:‣ J/ψ → e+e- ‣ 2.5 ≤ η ≤ 4.0, Δφ = 2π

RHIC: J/ψ in p+p at √s = 200 GeV

20

PHENIX and STAR results are consistent‣ High statistics ay low-pT from

PHENIX‣ High pT from STAR

PHENIX PRL 98, 232002 (2007)

STAR arXiv: 0806.0353 [nucl-ex]

RHIC: J/ψ in p+p at √s = 200 GeV

20

PHENIX PRL 98, 232002 (2007)

STAR arXiv: 0806.0353 [nucl-ex]

PHENIX PRL 98, 232002 (2007)STAR arXiv: 0806.0347 [nucl-ex]

BR(J/ψ→ℓ+ℓ-)σ(J/ψ) =178 ± 3(stat) ± 53(syst) ± 18(norm) nb

Theory: see talk by J.-P. Lansberg later

RHIC: ϒ in p+p at √s = 200 GeV

21

STAR 2006: ϒ+ϒ′+ϒ Bee×(dσ/dy)y=0=91±28(stat)±22(sys) pb

STAR 2008:Minimized material ⇒ less bremsstrahlung

First Look: ‣ Robust signal‣ Excellent S/B‣ Separation of ϒ

states possible

Compatible with world-data and NLO

STARPreliminary

First Measurements of Feeddown Contributionsψ′→ee χc→ee

Luminosity hungry measurements

First Measurements of Feeddown Contributions

22

PHENIX preliminary ‣ BRψ’→eeσ(ψ’) / BRJ/ψ→eeσ(J/ψ)

=0.019±0.005(stat)±0.002 (syst)‣ Feed-down fraction of J/ψ from ψ’:

R (ψ’) = 0.086 ± 0.025‣ R(ψ’) =8.1±0.3% from world average

(hep-ph/0809.2153v1)

ψ′→ee χc→ee

‣ R(χc) < 42% (90%C.L.)‣ R (χc) = 25% ± 5.0 world average

(hep-ph/0809.2153v1) (final Hera-B : 18% ± 2.8% hep-ex/08087.2167v1)

see talk by Pietro Faccioli

A new background at RHIC: B→J/ψ+X PHENIX & STAR: no Si vertex detectors yet

New Approach:• Study J/ψ-hadron azimuthal

correlations• For now: PYTHIA Simulations:

➡ prompt J/ψ (incl. ψ, χc feeddown) (NRQCD)

➡ B→J/ψ+X➡ Other, fragmentation, ... ?

• For pT(J/ψ) > 5 GeV/c:N(B→J/ψ):N(all J/ψ) ≈ (13±5)%

23

!"#$%&'()*+*,-'.%/01!%2%34

5"/01!"#6%7%8(91:

5"/3"#6%;<7%8(91:

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Promising method butNeed better theory constraints

24

d+A: Studying Cold Nuclear Matter EffectsConfusion on σabsJ/ψ also at RHIC

Phys Rev C 77, 024912

‣ PHENIX: σabsJ/ψ ~ 2.8 mb

dAu

24

d+A: Studying Cold Nuclear Matter EffectsConfusion on σabsJ/ψ also at RHIC

Phys Rev C 77, 024912

‣ PHENIX: σabsJ/ψ ~ 2.8 mb

dAu

‣ Error on breakup cross section are being re-evaluated

‣ Model dependent results- nuclear modified PDFs - Glauber geometry in d+Au

‣ Revised errors soon ... X

d+Au Measuring at Forward Rapidities

25

‣ α(x2=xAu) follows trend ?• Assumes 2 → 1 (see talk

by J.-P Lansberg)


25


by J.-P Lansberg)

‣ α does not scale with xF

‣ Another hint that we cannot capture all of the physics in the nPDF


25


by J.-P Lansberg)

‣ Soon more at larger xF

‣ α does not scale with xF

‣ Another hint that we cannot capture all of the physics in the nPDF

STAR FMS 2.5 ≤ η ≤ 4.0p+p & d+Au on tape

From test sample

Suppression in √sNN=200 GeV A+A 1. Suppression ∝ Centrality

2. Forward rapidity more suppressed than mid-rapidity• Ratio in Au+Au flat for

Npart > 100

26

nucl-ex/0611020Phys. Rev. Lett. 98 (2007) 232301

Au+Au

mid-rapidity

forward-rapidity

# of Participants ~ Centrality



Npart > 100

26

3. Suppression in Cu+Cu ≈ Au+Au within errors

Au+Au Phys Rev Lett 98:232301Cu+Cu: Phys Rev Lett 101:122301



Npart > 100

26


4. Suppression RHIC ≈ SPS

|y|<0.35

1.2<|y|<2.2PRL.98, 232301 (2007)arXiv:0801.0220



Npart > 100

26


4. Suppression RHIC ≈ SPS

|y|<0.35

1.2<|y|<2.2PRL.98, 232301 (2007)arXiv:0801.0220

Many Questions ‣ Recombination compensates stronger suppression? ‣ Cold matter effects? ‣ Melting of only higher states (+ small fraction of direct J/ψ)?

Cold Nuclear Matter Effects ?

27

‣ CNM effect is similar between both rapidities ‣ Stronger suppression than expectations from CNM effect‣ Need more d+Au data to constraint CNM effects.

Extrapolation from d+Au collisions:

Forward rapidityMid rapidity

Why regeneration explains rapidity trend?

‣ Uncorrelated c and c quarks coalesce at hadronization‣ At y≈0, more charm quarks ⇒ enhance the direct J/ψ yield

‣ Just an example below, a number of other models do as good a job

Dissociation versus Recombination?

28

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Sensitive to σcc(y): not too well known to-date

29

pT Dependence of Suppression

RHIC Cu+Cu: J/ψ for pT > 5 GeV/c:• STAR only: RAA = 1.2 ± 0.4 (stat) ± 0.2 (sys)• STAR + PHENIX: RAA = 0.96 ± 0.20(stat) ± 0.13(sys)

SPS In+In:• Consistent with no suppression at pT > 1.8 GeV

Recall that charm is massively suppresses at RHIC !!!Only way to escape the colored medium: color neutral object

!"#$%&'()

)*+,-.$*-$!/0/$,12/!34 5 6 7 8 9 : ; <

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R. Arnaldi (NA60) QM08

SPS/NA60

RHIC

Does the J/ψ Flow ?Recall: charm shows large v2 ⇒ c, c flow

J/ψ’s from recombination should inherit large charm-quark flow

30

First J/ψ flow measurement by PHENIX.• Limited statistics do not allow one to differentiate between models • Need more data ...

What’s next at RHIC?• Improve Understanding of CNM effects better

‣ 2008 d+Au run ⇒ more statistics

• Understand recombination contribution‣ Improve knowledge on c c production - y dependence‣ Vary √s, A

• Solid measurements of χc, ψ’ and ϒ family in p+p/d+Au/A+A‣ Requires more luminosity‣ ϒ better in many ways (e.g. no recombination) but σ small

31

What’s next at RHIC?• Improve Understanding of CNM effects better

‣ 2008 d+Au run ⇒ more statistics

• Understand recombination contribution‣ Improve knowledge on c c production - y dependence‣ Vary √s, A

• Solid measurements of χc, ψ’ and ϒ family in p+p/d+Au/A+A‣ Requires more luminosity‣ ϒ better in many ways (e.g. no recombination) but σ small

31

Ongoing RHIC Upgrades:1. RHIC stochastic cooling (~tenfold delivered luminosity)2. High-precision Si vertex tracking in STAR+PHENIX3. Improved PID, trigger, DAQ rate, ...

LHCA unique opportunity to investigate QGP at unparalleled high √sCMS & ATLAS have a solid HI programALICE is dedicated HI experiment

32


32

• All cross-section up × 30-50

‣ better statistics everywhere‣ but also new background sources


32

0

2

4

6

8

10

12

14

16

100 200 300 400 500 600

!SB/T4RHIC

LHC

SPS

3 flavor

2 flavor

2+1 flavor

0 flavor

T (MeV)

!/T

4

• All cross-section up × 30-50

‣ better statistics everywhere‣ but also new background sources

• Lifetime & Tinitial of plasma ~ 2 × RHIC

• Is it the same medium (sQGP versus wQGP)?

• Will need same level (or even more) of systematic studies than at RHIC to deconvolute suppression pattern from “ordinary” side effects

• Heavy-ion run in 2010?

SummaryRHIC• We see the, hottest, densest, matter, ever studied in the laboratory• Increasing evidence for a strongly couple plasma ⇒ sQGP• Next goal: Quantify properties such as EOS, transport coefficients, ...

33


33

Quarkonia• Less insights on the property of the plasma from quarkonia than originally

expected• Long systematic process to extract suppression

‣ Progress in many fronts: CNM, feed-down, ...‣ Next: ψ’, χc, ϒ(1S), ϒ(2S), ϒ(3S)‣ Need more luminosity

• Using quarkonia to probe the medium vs. using known medium to learn about quarkonia production


33

RHIC Upgrades & LHC: • New possibilities but also new challenges for HI

Quarkonia• Less insights on the property of the plasma from quarkonia than originally

expected• Long systematic process to extract suppression

‣ Progress in many fronts: CNM, feed-down, ...‣ Next: ψ’, χc, ϒ(1S), ϒ(2S), ϒ(3S)‣ Need more luminosity

• Using quarkonia to probe the medium vs. using known medium to learn about quarkonia production

Documents

Quarkonium Production in Heavy Ion Collisions · 2012. 10. 19. · Quarkonia not produced in QGP but produced statistically at hadronization from available c c pairs 13 Coalescence