Quarkonia production in heavy-ion collisions in...

Heavy Ion meeting 2013-127th December 2013

Quarkonia productionin heavy-ion collisions in CMS

Heavy Ion Meeting 2013-12Andong National University, Andong, Republic of Korea,

7th December 2013

Songkyo Lee(Korea University)

for the CMS collaboration

1

7th December 2013 Heavy Ion meeting 2013-12 2

Outline◍ Introduction ■ Motivation, CMS Detector

◍ Charmonia in PbPb collisions ■ Prompt J/ψ : RAA ■ Prompt J/ψ : azimuthal anisotropy

◍ Bottomonia in PbPb & pPb collisions ■ Υ(1S), Υ(2S) and Υ(3S)

◍ Summary


Motivation

◍ Debye screening ■ Loosely bound states (with smaller binding energies) melt at lower temperature. ■ Sequential melting of the quarkonia ⇒ Thermometer of QGP

◍ Quarkonia ■ Bound states of heavy quark and antiquark ■ Large mass requires a large momentum transfer only during the early stage of the collisions. ⇒ Powerful tool to probe QGP

T. Matsui & H. Satz, PLB 178 (1986) 416 Mocsy, EPJC 61 (2009) 705


CMS Detector


Muon Reconstruction

◍ Excellent muon Identification and triggering in the muon system◍ Outstanding momentum and vertex resolution of the tracking system

inner track Standalone muon

Global muon

7th December 2013 Heavy Ion meeting 2013-12

)2 (GeV/cµµm1 10 210

)2Ev

ents

/(GeV

/c

1

10

210

310

410

CMS Preliminary

-1bµ (PbPb) = 147 intL

= 2.76 TeVNNsPbPb ω, ρ φ

ψJ/

(2S)ψ(1,2,3S)ϒ

Z

> 4 GeV/cµ

Tp

6

Dimuons in PbPb @ 2.76 TeV


Prompt & Non-prompt J/ψ

PVSV

◍ Separation of prompt J/ψ and non-prompt J/ψ ■ 2-Dimentional simultaneous fit for mμμ & lJ/ψ

)2 (GeV/cµµm2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5

)2C

ount

s / (

0.02

GeV

/c

0

100

200

300

400

500

600

700

800 CMS Preliminary = 2.76 TeVNNsPbPb

-1bµ = 150 intL|y| < 2.4

< 8 GeV/cT

6.5 < pCent. 10-60%

2π| < RPΨ-ψJ/

φ0 < |

60±: 2619 ψJ/N2 1 MeV/c± = 47 σ

datatotal fitbkgd + non-promptbackground

(mm)ψJ/l-1 -0.5 0 0.5 1 1.5 2

Cou

nts

/ (0.

03 m

m)

1

10

210

310

410CMS Preliminary

= 2.76 TeVNNsPbPb -1bµ = 150 intL |y| < 2.4

< 8 GeV/cT

6.5 < pCent. 10-60%

2π| < RPΨ-ψJ/

φ0 < |datatotal fitbkgd + non-promptbackground

JHEP 05 (2012) 063

CMS-PAS HIN-12-014


Prompt J/ψ RAA◍ Nuclear modification factor

: RAA =1 No modification compared to pp collisions

Lint = 150μb-1

◍ Suppressed by factor ~5 in the most central bin◍ No pT and y dependent suppression is observed.

CMS-PAS HIN-12-014


J/ψ Azimuthal Anisotropy◍ Elliptic flow (v2) ■ Important to understand the dynamics of heavy-ion collision

◍ Reflected in the azimuthal distribution of particle yields

px pzpy

Initialgeometric

anisotropy

Finalmomentum anisotropy

=ΔΦ

CMS-PAS HIN-12-001

In non-central collisions

1

Ntotal

· d2N

d�/ 1 + 2v2cos(2��)

→ Asymmetry in the collective expansion → Path-length dependent absorption


Prompt J/ψ v2

partN0 50 100 150 200 250 300

2v

-0.05

0

0.05

0.1

0.15

0.2

0.25CMS Preliminary

= 2.76 TeVNNsPbPb -1bµ = 150 intL

ψPrompt J/ > 6.5 GeV/c

Tp|y| < 2.4

30-60% 20-30% 10-20%

GeV/cT

p0 5 10 15 20 25 30

2v

-0.05

0

0.05

0.1

0.15

0.2

0.25

|y| < 2.4

1.6 < |y| < 2.4

CMS Preliminary = 2.76 TeVNNsPbPb

-1bµ = 150 intL

ψPrompt J/Cent. 10 - 60 %

|y|0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4

2v

-0.05

0

0.05

0.1

0.15

0.2

0.25CMS Preliminary

= 2.76 TeVNNsPbPb -1bµ = 150 intL

ψPrompt J/Cent. 10 - 60 %

> 6.5 GeV/cT

p

◍ No strong centrality, pT, and rapidity dependence◍ Integrated v2 value (10-60%, 6.5 < pT < 30 GeV/c, |y| < 2.4 )

CMS-PAS HIN-12-001

‘First’ significant measurement of prompt J/ψ v2


Comparison with other hadronsCMS-PAS HIN-12-001

JHEP 1209 (2012) 112

GeV/cT

p0 2 4 6 8 10 12 14 16 18 20

2v

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45 = 2.76 TeVNNsPbPb

-1bµ = 150 intLCMS Preliminary

Cent. 10 - 60 %

±h|<0.8η|

ψPrompt J/<30 GeV/c

T|y|< 2.4, 6.5<p

ψPrompt J/<30 GeV/c

T1.6<|y|<2.4, 3<pALICE Prompt D, 30-50%

<16 GeV/cT

|y|<0.8, 2<p

◍ J/ψ v2 at lower pT region is much smaller than hadron v2 while higher pT region shows similar v2 values.◍ D meson v2 has similar trend to hadron rather than J/ψ.


Υ(nS) in PbPb

)2 (GeV/cµµm7 8 9 10 11 12 13 14

)2Ev

ents

/ ( 0

.1 G

eV/c

0

100

200

300

400

500

600

700

800

= 2.76 TeVNNsCMS PbPb

Cent. 0-100%, |y| < 2.4-1bµ = 150 intL

> 4 GeV/cµ

Tp

PreliminarydataPbPb fitpp shape

PbPb

pp fit

◍ In PbPb, Excited states are suppressed relative to the ground state.◍ The peak for Υ(3S) is hardly visible.

PRL 109 (2012) 222301

2011 pp


RAA for Υ(nS)

◍ Υ states are suppressed sequentially.

Υ(1S)

prompt J/ψ

Υ(2S)Υ(3S)

◍ Centrality integrated results

PRL 109 (2012) 222301

CMS-PAS HIN-12-014 RAA[Υ(1S)] > RAA[Υ(2S)] > RAA[Υ(3S)]


pPb collisions

◍ 1st pPb run @ LHC in Jan.-Feb. 2013 ■ √SNN = 5.02 TeV ■ Recorded luminosity by CMS : 31.7 nb-1

◍ Cold nuclear matter effects in pPb ■ Initial state energy loss, comover break up, shadowing, etc. ■ provide a better understanding of the effects from QGP ■ CNM itself is a interesting matter.


Υ(nS) in pPb from 2013

)2 (GeV/c-µ+µm7 8 9 10 11 12 13 14

)2Ev

ents

/ ( 0

.05

GeV

/c

0

100

200

300

400

500

600

700

800CMS Preliminary

= 2.76 TeVspp -1 = 5.1 pbintL

datatotal fitbackground

| < 1.93µ

CMη|

> 4 GeV/cµ

Tp

)2 (GeV/c-µ+µm7 8 9 10 11 12 13 14

)2Ev

ents

/ ( 0

.05

GeV

/c0

200

400

600

800

1000

1200

1400 CMS Preliminary = 5.02 TeVNNspPb

-1 = 31 nbintL


| < 1.93CMµη| > 4 GeV/cµ

Tp

CMS-PAS HIN-13-003

pPb

◍ Limited kinematic range(|yCM| < 1.93) due to the rapidity shift in the asymmetric p+Pb collisions◍ Fitting procedure is same in pp, pPb, and PbPb analysis.

2013 ppX20 more statisticsthan 2011 pp data


Double & Single ratios◍ Single Ratio

pPb

PbPb pPbPbPb

◍ pPb vs pp : Excited states are suppressed more than the ground state in pPb compared to pp.◍ PbPb vs pPb : Additional final state effects in PbPb that affect the excited states more than the ground state.

CMS-PAS HIN-13-003

pp

pp

◍ Double Ratio

pPb

PbPb


Event activity variables

|>4η|TE

1 10 210 310

(1S)

ϒ(n

s)/

ϒ

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5CMS Preliminary

|< 1.93CM

|y

(1S)ϒ(2S)/ϒ

pp 2.76 TeVpPb 5.02 TeVPbPb 2.76 TeV

|<2.4CM

|y

(1S)ϒ(3S)/ϒ

pp 2.76 TeVpPb 5.02 TeV

|<2.4η|tracksN

10 210 310

(1S)

ϒ(n

s)/

ϒ

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5CMS Preliminary

|< 1.93CM

|y

(1S)ϒ(2S)/ϒ

pp 2.76 TeVpPb 5.02 TeVPbPb 2.76 TeV

|<2.4CM

|y

(1S)ϒ(3S)/ϒ

pp 2.76 TeVpPb 5.02 TeV

pppPb

PbPb

pppPb

◍ Single ratios in all cases show the weaker dependence on ET. ◍ In pp and pPb, the significant decreasing dependence on Ntracks. ■ Υ would affect the multiplicity ? ■ Multiplicity would affect the Υ ?

pp

pPbPbPb

pp

pPb

raw transverse energymeasured in HF

corrected Ntracks in inner tracker


Summary

◍ Charmonia in PbPb collisions ■ prompt J/ψ is suppressed by factor 5 in the most central bin. ■ Significant anisotropy of prompt J/ψ in 10-60%, 6.5 < pT < 30 GeV/c, |y| < 2.4

◍ Bottomonia in PbPb & pPb collisions ■ Sequential melting of Υ(nS) is observed in PbPb. ■ Indication for the cold nuclear matter effect in pPb.


BACK-UP


pp, pPb, PbPb run at LHC & CMS ◍ 1st PbPb run @ √SNN = 2.76 TeV ■ Nov. - Dec. 2010 ■ Recorded luminosity by CMS : 7.28 μb-1

◍ 1st pp run @ √SNN = 2.76 TeV ■ March 2011 ■ Recorded luminosity by CMS : 225 nb-1

◍ 2nd PbPb run @ √SNN = 2.76 TeV ■ Nov. - Dec. 2011 ■ Recorded luminosity by CMS : 150 μb-1

◍ pPb run @ √SNN = 5.02 TeV ■ Jan. - Feb. 2013 ■ Recorded luminosity by CMS : 31.7 nb-1

◍ 2nd pp run @ √SNN = 2.76 TeV ■ Feb. 2013 (3 days) ■ Recorded luminosity by CMS : 5.41 pb-1

2010

2011

X20


Sequential melting scenario

r0

rλ(T)

r0>rλ(T)

◍ Cartoon for Debye screening ■ The larger the binding energy, the higher the dissociation temperature Td. ■ As temperature goes up, Debye length rλ(T) decreases.

ψ’

χc

J/ψ


Non-prompt J/ψ RAA

◍ Suppressed by factor ~3 in the most central bin◍ Hints of smaller suppression at lower pT region, mid-rapidity region

Information on the b-quark energy loss in medium

CMS-PAS HIN-12-014

Lint = 150μb-1


Prompt J/ψ RAA

partN0 50 100 150 200 250 300 350 400

AAR

0

0.2

0.4

0.6

0.8

1

1.2

1.4

|y|<1.21.2<|y|<1.61.6<|y|<2.4


ψPrompt J/

<30 GeV/cT

6.5<p

partN0 50 100 150 200 250 300 350 400

AAR

0

0.2

0.4

0.6

0.8

1

1.2

1.4

<30 GeV/cT

6.5<p<6.5 GeV/c

T3<p


ψPrompt J/

1.6<|y|<2.4

◍ Rapidity dependence ◍ pT dependence

◍ Left : No strong dependence on rapidity at high pT region◍ Right : At forward rapidity region, lower pT J/ψ is slightly less suppressed in the most central bins.


Non-prompt J/ψ RAA

partN0 50 100 150 200 250 300 350 400

AAR

0

0.2

0.4

0.6

0.8

1

1.2

1.4

|y|<1.21.2<|y|<1.61.6<|y|<2.4


ψNon-prompt J/

<30 GeV/cT

6.5<p

partN0 50 100 150 200 250 300 350 400

AAR

0

0.2

0.4

0.6

0.8

1

1.2

1.4

<30 GeV/cT

6.5<p<6.5 GeV/c

T3<p


ψNon-prompt J/

1.6<|y|<2.4

◍ Rapidity dependence ◍ pT dependence

◍ Left : In all rapidity bins at high pT region, centrality dependent suppression is shown.◍ Right : In the forward region, lower pT J/ψ has strong centrality dependence and less suppressed than high pT J/ψ.


ψ(2S) Single ratio

◍ Rψ(2s) in 0-20% PbPb ~ 2 times smaller than in pp

◍ 6.5 < pT < 30 GeV/c◍ |y|<1.6

◍ 3 < pT < 30 GeV/c◍ 1.6<|y|<2.4

◍ Rψ(2s) in 0-20% PbPb ~ 5 times larger than in pp

)2 (GeV/cµµm2.6 2.8 3 3.2 3.4 3.6 3.8 4 4.2

)2Ev

ents

/ ( 0

.04

GeV

/c

310


-1bµ = 150 intL

0-20%, 1.6 < |y| < 2.4 < 30 GeV/c

T3 < p

112±: 3510 ψJ/N 0.020±: 0.105 (2S)ψR

2 1) MeV/c± = (50 σ


)2 (GeV/cµµm2.6 2.8 3 3.2 3.4 3.6 3.8 4 4.2

)2Ev

ents

/ ( 0

.04

GeV

/c

210

310


-1bµ = 150 intL

0-20%, |y| < 1.6 < 30 GeV/c

T6.5 < p

65±: 3211 ψJ/N 0.008±: 0.024 (2S)ψR

2 1) MeV/c± = (29 σ


PbPb fit

PbPb 2011 pp

PbPb 2011 pp

CMS-PAS HIN-12-007

◍ Single ratio : R (2S) =N (2S)

NJ/


ψ(2S) Double ratio & RAA

partN0 50 100 150 200 250 300 350 400

pp]ψ

J/⁄(2

S)

ψ[⁄ Pb

Pb]

ψJ/⁄

(2S)

ψ[

0

1

2

3

4

5

6

7

8

9

10 = 2.76 TeVNNsPbPb

< 30 GeV/c, 1.6 < |y| < 2.4T

3 < p

pp uncertainty (global)

CMS Preliminary

partN0 50 100 150 200 250 300 350 400

0

0.2

0.4

0.6

0.8

1

1.2

1.4 = 2.76 TeVNNsPbPb

< 30 GeV/c, |y| < 1.6T

6.5 < p

pp uncertainty (global)

CMS Preliminary

high pTmid rapidity

region

lower pTforwardregion

(N (2S)/NJ/ )PbPb

(N (2S)/NJ/ )pp=

RAA( (2S))

RAA(J/ )

R0�100%AA ( (2S)) = 1.54±0.32(stat)±0.22(syst)±0.76(pp)

R0�100%AA ( (2S)) = 0.11±0.03(stat)±0.02(syst)±0.02(pp)

◍ Double ratio :

6.5<pT<30 GeV/c|y|<1.6

3<pT<30 GeV/c1.6<|y|<2.4

CMS-PAS HIN-12-007

limited by pp statistics◍ Centrality integrated results


Υ(nS) Double ratio in PbPb

◍ Υ(2S) double ratio vs centrality ■ No strong centrality dependence ■ Suppressed even in the most peripheral bin

◍ Υ(3S) double ratio vs centrality ■ Peak at PbPb is hard to distinguish. → Set the upper limit


Remark for pPb Υ analysis◍ Since the beam energy of proton and Pb nucleus is asymmetric, C.M frame is boosted by Δy ~ 0.47 w.r.t. lab frame.

◍ Symmetric range in C.M.frame [-1.93, 1.93] is selected for muon’s η and dimuon’s rapidity. : for the 1st run (proton going to -) : [-2.4, 1.47] : for the 2nd run (proton going to +) : [-1.47, 2.4]

HF HF

◍ Binning in 2 event activity variables : corrected Ntracks in inner tracker (|η|<2.4, pT>0.4 GeV/c) : raw transverse energy(ET) measured in HF (4<|η|<5.2)

inner tracker

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