Recent jet correlation analysis at RHIC and LHC
ShinIchi Esumi
Inst. of Physics
Univ. of Tsukuba
jet/photon suppression(RAA) / event anisotropy(v2)particle/jet correlation(IAA) / geometrical dependencemach-cone, ridge / soft-hard interplay
ridge in high mult. p+p events at LHC

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba1Jet quenching

No energy loss for γ‘s--- energy loss of parton in QGP ----- difference between hadron and direct photon ---!

Energy loss for quarkand gluon jets (similareven for heavy quark)

v2

RAA

Yield AA/"N binary # AA
R AA =
Yield pp

PHENIX preliminary

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba2

Understanding of high pT π0 v2 and RAA simultaneously--- assumption of a common origin : energy loss ---PRL105, 142301 (2010)

pT (GeV/c)

Models explaining measured RAA
do not usually explain measured v2 .

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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Two particle correlation (associate per trigger)--- two different features at low/high pT regions --PRL104, 252301 (2010), arXiv:1002.1077
IAA is slightly higher than RAA
less suppressed than singles
surface/tangential bias?

enhancement / suppression
broadening / un-modified shape

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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Reaction plane (path length) dependent energy loss--- one of dominant sources of v2 at high pT ---thickness dependenceof penetration is more
dominant thantangential surface
emission.

QM04: STAR

Heavy Ion Cafe, 30/Oct/2010, TokyoShinIchi Esumi, Univ. of Tsukuba

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J. Harris, hard probe 2010

(CDF)

(PHENIX)

Central Au+Au √sNN=200 GeV
STAR EMC + tracking data ETjet ~ 21 GeV

Heavy Ion Cafe, 30/Oct/2010, Tokyo

Central Pb+Pb √sNN=5.5 TeV
ALICE EMCal + tracking sim. ETjet ~ 120 GeV

ShinIchi Esumi, Univ. of Tsukuba

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Hard Probe 2010, Yue Shi Lai

single-jetsuppression

di-jet suppression
Hardprobe 2010, E. Bruna

Recoil Jet: R=0.4, pT,cut=2 GeV/c vs pT,cut=0.2 GeV/c
Trigger Jet: pT,cut=2 GeV/c, pT(trig)>20 GeV/c

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

7γ,Jet,π0 - hadron correlation--- Comparisons are the most important! ---cone size dependent jet suppression
can be understood by recovering ofenergy loss with a larger cone.
can be used to give a controlledbias in analysis and in triggering.

Heavy Ion Cafe, 30/Oct/2010, Tokyoto yr
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ShinIchi Esumi, Univ. of Tsukuba

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γ-Triggered Away-side Correlations:
Jet Fragmentation Function in p+p and Au+Au

total jet energy
is carried by γ

QM09 PHENIX

soft

ningo

fF.F.

inAu+Au•p+p: b = 6.89 ± 0.64
•Au+Au: b = 9.49 ±1.37

dN! bz= Ne TdzTzT = pTh / pT"

Heavy Ion Cafe, 30/Oct/2010, Tokyo!

IAAγ-had ~ RAAhad is naively expected and confirmed.
Slightly higher IAAπ0-had from surface/tangential bias.

ShinIchi Esumi, Univ. of Tsukuba

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Direct photons fromSTAR experiment

Hardprobe 2010, J. Putschke

hadron v2

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

10Jet - hadron correlation
High Tower Trigger (HT) : (ηxφ)=(0.05x0.05) ET>5.4GeV

RHIC-AGS’09, J. Putschke

Hardprobe 2010, J. Putschke

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba11

Back-to-back Jet Calorimeter
for LHC-ALICE experiment

D-CAL upgrade
Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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QM09: PHENIXc2(data) - c2(flow)

in-planetrigger selection(4) φs=[-1,0]π/8(5) φs=[0,1]π/8(3) φs=[-2,-1]π/8(6) φs=[1,2]π/8(2) φs=[-3,-2]π/8(7) φs=[2,3]π/8

Geometrical dependence
or effect from expansion?
200GeV Au+Au -> h-h
mid-central : 20-50%
pTTrig=2~4GeV/cpTAsso=1~2GeV/cin-plane
associate
regions(1)(2)

out-of-plane
trigger selection

average

(7)

(3)

(6)

(4)

(5)

(5)

(4)

(6)

(3)

(7)

relatively lower pT
left/right trigger w.r.t. R.P.
left/right associate w.r.t. trigger(1) φs=[-4,-3]π/8(8) φs=[3,4]π/8(8)strong preference of associateparticle emission towards thein-plane (thinner) direction

in-plane

(2)
(8)

(1)

φs = φTrig. − ΦR.P.
[−π/2,π/2]

not significant but
some reversed trend
at out-of-plane

PHENIX preliminaryΔφ = φAsso. − φTrig. (rad)Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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the same data in polar plots (R.P. is x axis)--- associate distribution for a given trigger direction --out-of-plane trigger
3π/8 < | φTrig. - φR.P. | < π/2

200GeV Au+Au -> h-h(pTTrig=2~4GeV/c, pTAsso=1~2GeV/c)
in-plane trigger| φTrig. - φR.P. | < π/8

averaged over
all trigger angles

central(0-20%)
mid-central(20-50%)

R.P.

peripheral(50-93%)

base line

Heavy Ion Cafe, 30/Oct/2010, TokyoTrigger angle

PHENIX preliminary

ShinIchi Esumi, Univ. of Tsukuba

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the same data in polar plots (R.P. is x axis)--- associate distribution for a given trigger direction --out-of-plane trigger
3π/8 < | φTrig. - φR.P. | < π/2

200GeV Au+Au -> h-h(pTTrig=2~4GeV/c, pTAsso=1~2GeV/c)
in-plane trigger| φTrig. - φR.P. | < π/8

penetration

mid-central(20-50%)

R.P.R.P.

central(0-20%)

surfaceaveraged over
all trigger angles

peripheral(50-93%)

base line

Heavy Ion Cafe, 30/Oct/2010, Tokyo

Trigger angle

PHENIX preliminary

ShinIchi Esumi, Univ. of Tsukuba

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SQM09, F. Wang

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

ShinIchi Esumi, Univ. of Tsukuba

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nothing left?

nothing left?

Hard Probe 2010, G. Roland

R.P. dependence (left/right asymmetry) still holds

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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Δφ = φasso − φtrigΔη = ηasso − ηtrig

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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PHENIX data analysis is in progress byTakahito Todoroki,
STAR data analysis is about to start…

Δφ = φasso − φtrig

Δη = ηasso − ηtrig

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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pythia8 : Ryo Funatoηtrig<0ηtrig>0Δη = ηasso - ηtrig
Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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ATHIC2008
in Tsukuba,S. Esumi

triggerIAPY THyΔφx(1)(2)(3)(4)(5)(6)
(7)
(8)

p+p

away side

near side

away side of a back-to-back(b-t-b) jet is wider in η than in φ
If there are two parallel b-t-b jets, away side of one b-t-b jet can benear side of the another b-t-b jet.
Suppression as well as modification of b-t-b jet would depend on
relative angle w.r.t. almond geometry, we know this from v2
measurement and believe this is the major source of v2 at high pT .
Therefore, there should be inter b-t-b jets correlation give by thegeometry from (3), this could make near side ridge like effect,
especially if the effect (3) has shaper dependence than v2(=cos2x).
We always measure inclusive v2, which includes the effect (3).
Therefore any modification which could generates the elliptic
anisotropy would be included in the measured v2 .
We subtract BG contribution with this v2 from (5) by maximizing
BG contribution assuming zero jet yield at minimum at any dφ.
If near and away side jets overlap each other, this subtraction
underestimates the jet yield and can change the extracted jet shape.
If you extract angular dependence of jet w.r.t. R.P., the results will
easily be affected by the choice of v2 from (5).

Heavy Ion Cafe, 30/Oct/2010, TokyoΔη

ShinIchi Esumi, Univ. of Tsukuba)Δφ(rad22

CMS, CERN Seminar, Sept. 21, 2010
CERN-PH-EP/2010-031
arXiv:1009.4122v1

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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Heavy Ion Cafe, 30/Oct/2010, Tokyo

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Heavy Ion Cafe, 30/Oct/2010, Tokyo

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Ridge is seen at high multiplicity p+p(LHC)
CMS, CERN Seminar, Sept. 21, 2010
CERN-PH-EP/2010-031
arXiv:1009.4122v1
long range correlation is also seenat ISR, SppS, Fermi lab.
consistent with CGC picture?
what if there is v2 in p+p?

seen in Au+Au at RHIC, but not in Cu+Cu?
remember a large v2 in Cu+Cu at RHIC
εSTD ~ εpart (Au+Au)εSTD << εpart (Cu+Cu)

Hard Probe 2010,J. Putschke

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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CERN-ISR
Nucl. Phys. B145
(1978) 305-348

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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Summary
jet/photon suppression(RAA) / event anisotropy(v2)particle/jet correlation(IAA) / geometrical dependencemach-cone, ridge / soft-hard interplay
ridge in high mult. p+p events at LHC

Heavy Ion Cafe, 30/Oct/2010, Tokyo

ShinIchi Esumi, Univ. of Tsukuba

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