Centrality and rapidity dependence of inclusive jet production in s - - PowerPoint PPT Presentation

SLIDE 1

Dennis V. Perepelitsa Brookhaven National Laboratory for the ATLAS Collaboration

Centrality and rapidity dependence of inclusive jet production in √sNN = 5.02 TeV p+Pb collisions with the ATLAS detector

20 May 2014 XXIV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

• Darmstadt, Germany

SLIDE 2

Hard probes of p(d)+A

• Hard probes access the partonic structure of the nucleus
• Jets allow us to explore this over a large kinematic range
• Can probe b-dependent nPDFs, initial state energy loss, saturation

phenomena (at very low pT, large y*), etc.

2

Albacete et al., hep-ph/1209.2001 η-dependence of CGC vs. nPDF predictions

2 4 6 8 10 12 0.5 1 1.5 2 0.5 1 1.5 2

IP-Sat (Tribedy & Venugopalan) rcBK (Tribedy & Venugopalan)

RpPb(=0)

ch EPS09 nPDF

pt (GeV/c)

rcBK-MC kt-factorization 2 4 6 8 10 12 0.5 1 1.5 2 0.5 1 1.5 2

RpPb(=4)

rcBK-MC, min bias rcBK-MC, LO+inelastic term =0.1

pt (GeV/c)

rcBK-MC, Npart >10 ch cme= 5 TeV EPS09 nPDF

η>0 is proton-going

2 4 6 8 10 12 0.5 1 1.5 2 0.5 1 1.5 2

RpPb(=2)

ch rcBK-MC, hyb LO+inel. term =0.1

pt (GeV/c)

rcBK-MC, hybrid LO rcBK-MC, kt-factorization EPS09 nPDF 2 4 6 8 10 12 0.5 1 1.5 2 0.5 1 1.5 2

RpPb(=6)

rcBK-MC, min bias rcBK-MC, LO+inelastic term =0.1

pt (GeV/c)

rcBK-MC, Npart >10 ch cme= 5 TeV EPS09 nPDF

x

• 5

10

• 4

10

• 3

10

• 2

10

• 1

10 1 0.2 0.4 0.6 0.8 1 1.2 1.4 EPS09 HKN nDS

)

2

=100 GeV

2

(x,Q

Pb g

R

FGS10

Salgado et al., hep-ph/1105.3919 current best knowledge of nPDFs

SLIDE 3

Hard probes of p(d)+A @ RHIC

• What happens in central & peripheral collisions in between?

➡ ATLAS can explore the kinematic range in the middle

3

• At forward rapidity, large centrality

dependent suppression

• single- and di-hadrons
• attributed to shadowing / saturation

/ CGC phenomena

c e n t r a l peripheral

• At mid-rapidity, anomalous centrality

dependence

• for high-pT jets
• central suppression
• enhanced peripheral (!?)

Au frag

x

• 3

10

• 2

10

dA

J

• 1

10 1

T fwd

d+Au 60-88 p 0.5-0.75 GeV/c 0.75-1.0 GeV/c 1.0-1.5 GeV/c

T fwd

d+Au 0-20 p 0.5-0.75 GeV/c 0.75-1.0 GeV/c 1.0-1.5 GeV/c

(GeV/c)

rec T

p 10 15 20 25 30 35 40

dA

R 0.4 0.6 0.8 1 1.2 1.4 1.6

= 200 GeV

NN

s d+Au,

=0.3 Gaussian filter jet, 0-20% σ =0.3 Gaussian filter jet, 60-88% σ

• jet RdAu

di-hadron JdA 60-88% 0-20%

PRL 107 172301 (2011)

10.1016/j.nuclphysa.2013.02.184

SLIDE 4

4

ATLAS detector

Inner Detector

• 2.5 < η < +2.5

Pb-going Forward Calorimeter

• 4.9 < η < -3.2

EMCal+HCal system

• 4.9 < η < +4.9

Pb

p

Convention: y* > 0 is proton-going

+ High Level Trigger system

SLIDE 5

p+Pb collisions & centrality

• 28 nb-1 of p+Pb/Pb+p data @ 5.02 TeV
• Centrality determined using ΣET in Pb-going

FCal, -4.9 < η < -3.2, default Glauber

• best sensitivity to collision geometry & allows

measurements of very forward jets

• Reasonable behavior in soft & hard observables

η

• 3
• 2
• 1

1 2 3 )

60-90%

| η /d

ch

) / (dN

cent.

| η /d

ch

(dN 1 2 3 4 5 6 7 8 9

ATLAS Preliminary

• 1

b µ = 1

int

p+Pb L = 5.02 TeV

NN

s = -0.465

cm

y

0-1% 1-5% 5-10% 10-20% 20-30% 30-40% 40-60%

[GeV]

Pb T

E Σ 100 200 [1/GeV]

Pb T

E Σ /d N d

evt

N 1/

• 6

10

• 5

10

• 4

10

• 3

10

• 2

10

ATLAS Preliminary

= 5.02 TeV

NN

s +Pb, p

• 1

dt = 27.8 nb L

∫

10 20 30

)

events

N 〉

coll

N 〈 /(

Z

N

9

10 2 4 6 8 10 12 10 ×

Preliminary ATLAS

• 1

=29 nb

int

p+Pb 2013, L = 5.02 TeV

NN

s 0-90% Centrality <2.5

Z

• 2.5<y

Data Uncertainty 〉

coll

N 〈 NNLO Prediction =0) Ω Glauber (

〉

part

N 〈

10 20 30

5

• Z. Citron, 14:40 Tuesday

Ncoll-scaling of Z production in p+Pb

• R. Debbe, 10:30 Monday

ATLAS-CONF-2014-020 ATLAS-CONF-2013-096

SLIDE 6

Jets in p+Pb

6

[GeV]

T

p

]

• 1

*) [GeV y d

T

p N/d

2

)(d

evt

(1/N

• 12

10

• 10

10

• 8

10

• 6

10

• 4

10

• 2

10 1

2

10

4

10

6

10

8

10

1 × +3.6 < y* < +4.4,

1

10 × +2.8 < y* < +3.6,

2

10 × +2.1 < y* < +2.8,

3

10 × +1.2 < y* < +2.1,

4

10 × +0.8 < y* < +1.2,

5

10 × +0.3 < y* < +0.8,

6

10 ×

• 0.3 < y* < +0.3,

7

10 ×

• 0.8 < y* < -0.3,

8

10 ×

• 1.2 < y* < -0.8,

9

10 ×

• 2.1 < y* < -1.2,

= 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

∫

• 1

dt = 27.8 nb L 0-90%

ATLAS

Preliminary

20 100 1000

• anti-kt, R=0.4 calorimeter jets
• UE estimation & subtraction
• designed for Pb+Pb, cross-checked in pp
• Selected by online high-level jet trigger
• 36m PYTHIA pp dijets overlaid onto p+Pb data
• corrections are modest (10-30%)
• and mostly cancel in the RCP and RpPb

0-90% yields

See poster E-15 by T. Kosek

SLIDE 7

Jet RpPb

7

+2.1 < y* < +2.8 ATLAS Preliminary +0.8 < y* < +1.2

• 0.3 < y* < +0.3
• 1.2 < y* < -0.8

= 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+1.2 < y* < +2.1

+Pb, 0-90% p EPS09 calculation

+0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

∫

• 1

dt = 27.8 nb

pPb

L

∫

• 1

dt = 4.0 pb

pp

L

1.6 1.0 0.4 1.6 1.0 0.4 1.6 1.0 0.4 1.6 1.0 0.4

pPb

R

40 100 1000 40 100 1000 [GeV]

T

p

y*>0 is proton-going

RpPb =

(1/Nevt) d2N/dpTdy* <TpA> d2σ/dpTdy*

jet yield in p+Pb

Pb nucleon flux seen by proton

2013 pp data @ 2.76 TeV (xT-scaled to 5.02 TeV)

• RpPb for 0-90% events
• ≈5 units of rapidity, 50-1000 GeV
• 5-10% enhancement
• weak pT dependence?
• consistent with EPS09 prediction

SLIDE 8

Jet RCP

+3.6 < y* < +4.4 ATLAS

Preliminary

+2.1 < y* < +2.8 +0.8 < y* < +1.2

• 0.3 < y* < +0.3
• 1.2 < y* < -0.8

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+2.8 < y* < +3.6 +1.2 < y* < +2.1 +0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

0-10%/60-90% 20-30%/60-90% 40-60%/60-90%

1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4

CP

R

20 100 800 20 100 800 [GeV]

T

p

0-10%/60-90% 20-30%/60-90% 40-60%/60-90%

• > 100 GeV jets

suppressed at mid-rapidity!

• suppression

pattern smooth with centrality

• larger

suppression at higher pT

y*>0 is proton-going

8

RCP =

Rcoll

central yield

Ncoll ratio

peripheral yield

(1/Nevt) d2N/dpTdy* (1/Nevt) d2N/dpTdy*

SLIDE 9

Jet RCP

RCP ≈ 0.2 here!

• increasing

suppression at more forward rapidities

• 9

+3.6 < y* < +4.4 ATLAS

Preliminary

+2.1 < y* < +2.8 +0.8 < y* < +1.2

• 0.3 < y* < +0.3
• 1.2 < y* < -0.8

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+2.8 < y* < +3.6 +1.2 < y* < +2.1 +0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

0-10%/60-90% 20-30%/60-90% 40-60%/60-90%

1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4

CP

R

20 100 800 20 100 800 [GeV]

T

p 9

y*>0 is proton-going

SLIDE 10

Jet RCP

suppression even at backward rapidities

+3.6 < y* < +4.4 ATLAS

Preliminary

+2.1 < y* < +2.8 +0.8 < y* < +1.2

• 0.3 < y* < +0.3
• 1.2 < y* < -0.8

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+2.8 < y* < +3.6 +1.2 < y* < +2.1 +0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

0-10%/60-90% 20-30%/60-90% 40-60%/60-90%

1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4

CP

R

20 100 800 20 100 800 [GeV]

T

p

y*>0 is proton-going

thus, the data is incompatible with a centrality- dependent y* “shift”

10

SLIDE 11

Jet RCP

How does this make sense with the RpPb?

+3.6 < y* < +4.4 ATLAS

Preliminary

+2.1 < y* < +2.8 +0.8 < y* < +1.2

• 0.3 < y* < +0.3
• 1.2 < y* < -0.8

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+2.8 < y* < +3.6 +1.2 < y* < +2.1 +0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

0-10%/60-90% 20-30%/60-90% 40-60%/60-90%

1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4 1.4 1.0 0.4

CP

R

20 100 800 20 100 800 [GeV]

T

p

y*>0 is proton-going

Modification pattern over 6.5 units of rapidity, from 25-800 GeV!

11

SLIDE 12

Jet RpPb

➡ Centrality-selected RpPb must

split the difference

• 0-10% RpPb suppressed
• 60-90% RpPb enhanced(!)
• Larger modifications at high-pT

and forward rapidities

➡ Backwards & at low pT, we

recover geometric scaling

+2.1 < y* < +2.8 +0.8 < y* < +1.2

• 0.3 < y* < +0.3

ATLAS

Preliminary

• 1.2 < y* < -0.8

= 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+1.2 < y* < +2.1

0-10% 20-30% 60-90%

+0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

∫

• 1

dt = 27.8 nb

pPb

L

∫

• 1

dt = 4.0 pb

pp

L

1.6 1.0 0.4 1.6 1.0 0.4 1.6 1.0 0.4 1.6 1.0 0.4

pPb

R

40 100 1000 40 100 1000 [GeV]

T

p

y*>0 is proton-going

12

SLIDE 13

Jet RpPb

+2.1 < y* < +2.8 +0.8 < y* < +1.2

• 0.3 < y* < +0.3

ATLAS

Preliminary

• 1.2 < y* < -0.8

= 5.02 TeV

NN

s +Pb p =0.4 R ,

t

k anti-

+1.2 < y* < +2.1

0-10% 20-30% 60-90%

+0.3 < y* < +0.8

• 0.8 < y* < -0.3
• 2.1 < y* < -1.2

∫

• 1

dt = 27.8 nb

pPb

L

∫

• 1

dt = 4.0 pb

pp

L

1.6 1.0 0.4 1.6 1.0 0.4 1.6 1.0 0.4 1.6 1.0 0.4

pPb

R

40 100 1000 40 100 1000 [GeV]

T

p

y*>0 is proton-going

13

How can we understand the rapidity dependence?

SLIDE 14

Scaling in the RCP vs. p

14

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p 0-10% =0.4 R ,

t

k anti-

ATLAS

Preliminary

+3.6 < y* < +4.4 +2.8 < y* < +3.6 +2.1 < y* < +2.8 +1.2 < y* < +2.1 +0.8 < y* < +1.2 +0.3 < y* < +0.8

• 0.3 < y* < +0.3
• 0.8 < y* < -0.3
• 1.2 < y* < -0.8
• 2.1 < y* < -1.2

1.4 1.0 0.4

CP

R 40 100 1000 40 100 1000 cosh(<y*>) [GeV] ×

T

p

• Replot the RCP at all rapidities vs. p = pT cosh(y*)
• — e.g. the total jet energy

y* > 0 data follow a single trend! RCP(pT, y*) = RCP(p) y* < 0 data do not…

What is this telling us about the suppression mechanism?

SLIDE 15

Scaling in the RpPb vs. p

15

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p 0-10% =0.4 R ,

t

k anti-

ATLAS Preliminary

+2.1 < y* < +2.8 +1.2 < y* < +2.1 +0.8 < y* < +1.2 +0.3 < y* < +0.8

60-90%

1.6 1.0 0.4

pPb

R 40 100 1000 40 100 1000 cosh(<y*>) [GeV] ×

T

p

CENTRAL PERIPHERAL

• At high pT, central and peripheral RpPb scale with p separately!
• Events with a forward jet with energy p typically have xp = p / (√s/2)
• are we learning something about the proton wavefunction?

SLIDE 16

Conclusion

• ATLAS has measured inclusive jets in p+Pb collisions
• RpPb for > 50 GeV, -2.1 < y* < +2.8
• RCP for > 30 GeV (at forward rapidities), -2.1 < y* < +4.4
• The jet rate in 0-90% p+Pb collisions is mildly enhanced
• consistent with nPDF expectations
• Strong, centrality dependent effects in the RCP & RpPb
• geometric scaling at low pT
• at high pT, suppression/enhancement in central/peripheral RpPb
• large changes in the number of partons available for hard scattering?
• or strong correlation between scattering kinematics and soft interactions?
• challenging for factorization pictures of hard processes in nuclei
• The modifications exhibit a continuous y* dependence that can be described

in terms of simple kinematics alone

16

SLIDE 17

Conclusion

• The modifications exhibit a continuous y* dependence that can be

described in terms of simple kinematics alone

17

⇒ https://twiki.cern.ch/twiki/bin/view/AtlasPublic/HeavyIonsPublicResults ⇐

ATLAS-CONF-2014-033

∫

• 1

dt = 27.8 nb L = 5.02 TeV

NN

s +Pb p 0-10% =0.4 R ,

t

k anti-

ATLAS

Preliminary

+3.6 < y* < +4.4 +2.8 < y* < +3.6 +2.1 < y* < +2.8 +1.2 < y* < +2.1 +0.8 < y* < +1.2 +0.3 < y* < +0.8

• 0.3 < y* < +0.3
• 0.8 < y* < -0.3
• 1.2 < y* < -0.8
• 2.1 < y* < -1.2

1.4 1.0 0.4

CP

R 40 100 1000 40 100 1000 cosh(<y*>) [GeV] ×

T

p

SLIDE 18

Backup: pp reference

18

[GeV]

T

p [ nb/GeV ] y d

T

p d σ

2

d

• 5

10

• 4

10

• 3

10

• 2

10

• 1

10 1 10

2

10

3

10

4

10

5

10

6

10

7

10

8

10

9

10

10

10

11

10 40 60 100 200 400

)

8

10 × | < 2.1 ( y | )

6

10 × | < 0.3 ( y | )

4

10 × | < 0.8 ( y | ≤ 0.3 )

2

10 × | < 1.2 ( y | ≤ 0.8 ) 10 × | < 2.1 ( y | ≤ 1.2

Preliminary ATLAS

= 2.76 TeV s =0.4, R

t

k anti-

• 1

= 4.0 pb

int

L data, pp 2013

1 1.5 2

|y| < 0.3

0.5 1 1.5 2 2.5

|y| < 0.8

• 0.3

1 1.5 2

|y| < 1.2

• 0.8

0.5 1 1.5 2

|y| < 2.1

• 1.2

1 2 3

|y| < 2.8

• 2.1

1 2 3

|y| < 3.6

• 2.8

1 2 3

|y| < 4.4

• 3.6

T

x

• 2

10 × 2

• 1

10

• 1

10 × 2

T

x

• 2

10 × 2

• 1

10

• 1

10 × 2

)

T

(y, x

• )

T

(y, x

• ATLAS
• 1

dt = 0.20 pb L

• jet

7TeV

• jet

2.76TeV

• 3

7TeV 2.76TeV

=

• R = 0.4

t

k anti-

Data with statistical uncertainty Systematic uncertainties

• NLO pQCD

non-pert. corr.

)

max T

=p µ (CT10,

ATLAS-CONF-2014-025 ATLAS, hep-ph/1304.4739

• pp jet cross-section, high-statistics February 2013 running
• same reconstruction procedure & corrections as in p+Pb data
• consistent with 2.76 TeV pp jet cross-section from 2011 running & NLO calculations
• ATLAS measurement of xT scaling between 2.76 and 7 TeV
• full treatment of correlations in systematic uncertainties
• we interpolate to 5.02 TeV between two ATLAS data measurements

SLIDE 19

Backup: jet performance

19

3

[GeV]

reco T

p

10 100 1000

* < +0.3 y

• 0.3 <

3 2

10

3

10

• 9

10

• 8

10

• 7

10

• 6

10

• 5

10

• 4

10

• 3

10

• 2

10

• 1

10 1 10

2

10

3

10

* < -0.8 y

• 1.2 <

[GeV]

truth T

p [GeV]

reco T

p

* < -2.8 y

• 2.1 <

10 100 1000 10 100 1000

[GeV]

truth T

p

2

10

3

10

• 9

10

• 8

10

• 7

10

• 6

10

• 5

10

• 4

10

• 3

10

• 2

10

• 1

10 1 10

2

10

3

10 10 100 1000

* < -4.4 y

• 3.6 <

ATLAS Simulation Preliminary +Pb, 5.02 TeV p , R=0.4

t

k anti-

[GeV]

truth T

p

JES Closure

• 0.02

0.02 0.04 0.06 20 100 1000

* < +0.3 y

• 0.3 <

* < -0.8 y

• 1.2 <

* < -2.1 y

• 2.8 <

* < -3.6 y

• 4.4 <

[GeV]

truth T

p JER

0.05 0.1 0.15 0.2 20 100 1000

ATLAS Simulation Preliminary +Pb, 5.02 TeV p , R=0.4

t

k anti-

Also see poster E-15 by T. Kosek ATLAS-CONF-2013-096

• Jet Energy Scale Closure (<pTreco/pTtruth - 1>) always better than 2%
• typically 1%, with small centrality-dependent differences at low pT
• Jet Energy Resolution σ(pTreco/pTtruth - 1), 7-20%, pT and y* dependent
• Bin-by-bin correction factors typically 10-30%, but largely cancel in

the RCP and RpPb ratios anyway

SLIDE 20

Backup: xp dependence?

20

• Coleman-Smith, Mueller

hep-ph/1307.5911

Np=0 Np=1 Np=2 Np=3

0.01 0.02 0.05 0.10 0.20 0.50 1.00 10-5 10-4 0.001 0.01 0.1 1

x x PqHx»NpL

<Np>=0.177

10-4 0.001 0.01 0.1 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

x fNpHxLêfHxL

Alvioli, Frankfurt, Guzey, Strikman hep-ph/1402.2868

Idea: (anti-)correlation between proton wave function with large transverse extent and high x?

1 2 3 4 5 6 5 10 15 20 25

PN

Hard(σ) / PN Hard(σtot)

Ncoll (a) Glauber, σ = σtot/2 Glauber, σ = σtot/4 Glauber+CF, <σ> = σtot/2 Glauber+CF, <σ> = σtot/4

SLIDE 21

Backup: centrality “bias”?

21

• Much discussion of a centrality “bias”: event activity reflecting the

presence of a hard process in additional to just the collision geometry

• 1. All result in increases/decreases in central/peripheral events
• 2. All show a weaker “bias” farther from the centrality-determining detector

➡ the ATLAS data show the opposite effects

• The ATLAS data show an entirely different phenomenon

0.8 1 1.2

0-20%

(a)

Correction 0.8 1 1.2

20-40%

(b)

Bias Factor

0.8 1 1.2

40-60%

(c)

0.5 1 1.5

60-80%

(d)

[GeV/c]

T

p 5 10 15 20 25 30 35 40 45 50 1 2 3 4

80-100%

(e)

PHENIX bias correction factors nucl-ex/1310.4793

• A. Toia, 16:50 Monday
• S. Campbell,

12:20 Monday

SLIDE 22

Backup: dominant systematics

22

1 1.5 2

|y| < 0.3

0.5 1 1.5 2 2.5

|y| < 0.8

• 0.3

1 1.5 2

|y| < 1.2

• 0.8

0.5 1 1.5 2

|y| < 2.1

• 1.2

1 2 3

|y| < 2.8

• 2.1

1 2 3

|y| < 3.6

• 2.8

1 2 3

|y| < 4.4

• 3.6

T

x

• 2

10 × 2

• 1

10

• 1

10 × 2

T

x

• 2

10 × 2

• 1

10

• 1

10 × 2

)

T

(y, x

• )

T

(y, x

• ATLAS
• 1

dt = 0.20 pb L

• jet

7TeV

• jet

2.76TeV

• 3

7TeV 2.76TeV

=

• R = 0.4

t

k anti-

Data with statistical uncertainty Systematic uncertainties

• NLO pQCD

non-pert. corr.

)

max T

=p µ (CT10,

centrality

6

• 9

% 4

• 6

% 3

• 4

% 2

• 3

% 1

• 2

% 5

• 1

% 1

• 5

%

• 1

%

• 9

%

〉

part

N 〈

5 10 15 20 25 30

Simulation Preliminary ATLAS = 5.02 TeV

NN

s p+Pb,

• 1

b µ = 1

int

L Glauber = 0.55 Ω Glauber-Gribov = 1.01 Ω Glauber-Gribov

• Systematics on the ratios of p+Pb/pp spectra are small
• same detector, same running period, same analysis procedure
• For RpPb, dominant systematics are from the xT interpolation (6-15%)

and TpA

• For RCP, dominant systematics are actually from Rcoll

ATLAS, hep-ph/1304.4739 ATLAS-CONF-2013-096

SLIDE 23

Backup: implications for quenching in Pb+Pb?

23

ATLAS-CONF-2014-025

https://twiki.cern.ch/twiki/pub/CMSPublic/HIRaaCompilation

) [GeV]

T

(m

T

p

1 10

2

10

AA

R

0.5 1 1.5 2 2.5

• 1

b µ L dt = 7-150

∫

= 2.76 TeV

NN

s CMS *PRELIMINARY PbPb

*Z (0-100%) |y| < 2 | < 2.1

µ

η , | > 25 GeV/c

µ T

W (0-100%) p | < 1.44 η Isolated photon (0-10%) | | < 1 η Charged particles (0-5%) | | < 2.4 η (0-100%) | ψ J/ → *B | < 2 η *Inclusive jet (0-5%) | | < 2 η *b-jet (0-10%) |

AA

R

0.5 1 | < 2.1 y |

Preliminary ATLAS

= 0.4 jets R

t

k anti- = 2.76 TeV

NN

s

• 1

= 0.14 nb

int

L 2011 Pb+Pb data,

• 1

= 4.0 pb

int

L data, pp 2013

AA

R

0.5 1 | < 0.8 y 0.3 < | 0 - 10 % 30 - 40 % 60 - 80 %

[GeV]

T

p

AA

R

0.5 1 40 60 100 200 400 40 60 100 200 400 40 60 100 200 400 | < 2.1 y 1.2 < | 0 - 10 % 30 - 40 % 60 - 80 %

• A. Angerami,

Tuesday 10:00