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
7th December 2013 Heavy Ion meeting 2013-12 3
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
7th December 2013 Heavy Ion meeting 2013-12 4
CMS Detector
7th December 2013 Heavy Ion meeting 2013-12 5
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
7th December 2013 Heavy Ion meeting 2013-12 7
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
7th December 2013 Heavy Ion meeting 2013-12 8
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
7th December 2013 Heavy Ion meeting 2013-12 9
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
7th December 2013 Heavy Ion meeting 2013-12 10
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
7th December 2013 Heavy Ion meeting 2013-12 11
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.
7th December 2013 Heavy Ion meeting 2013-12 12
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
7th December 2013 Heavy Ion meeting 2013-12 13
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)]
7th December 2013 Heavy Ion meeting 2013-12 14
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.
7th December 2013 Heavy Ion meeting 2013-12 15
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
datatotal fitbackground
| < 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
7th December 2013 Heavy Ion meeting 2013-12 16
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
7th December 2013 Heavy Ion meeting 2013-12 17
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
7th December 2013 Heavy Ion meeting 2013-12 18
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.
7th December 2013 Heavy Ion meeting 2013-12 19
BACK-UP
7th December 2013 Heavy Ion meeting 2013-12 20
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
7th December 2013 Heavy Ion meeting 2013-12 21
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
7th December 2013 Heavy Ion meeting 2013-12 22
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
7th December 2013 Heavy Ion meeting 2013-12 23
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
CMS Preliminary = 2.76 TeVNNsPbPb
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
CMS Preliminary = 2.76 TeVNNsPbPb
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.
7th December 2013 Heavy Ion meeting 2013-12 24
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
CMS Preliminary = 2.76 TeVNNsPbPb
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
CMS Preliminary = 2.76 TeVNNsPbPb
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.
7th December 2013 Heavy Ion meeting 2013-12 25
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
CMS Preliminary = 2.76 TeVNNsPbPb
-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
datatotal fitbackground
)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
CMS Preliminary = 2.76 TeVNNsPbPb
-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
datatotal fitbackground
PbPb fit
PbPb 2011 pp
PbPb 2011 pp
CMS-PAS HIN-12-007
◍ Single ratio : R (2S) =N (2S)
NJ/
7th December 2013 Heavy Ion meeting 2013-12 26
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
7th December 2013 Heavy Ion meeting 2013-12 27
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
7th December 2013 Heavy Ion meeting 2013-12 28
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