post%QM(2014(mee/ng(@Nagoya!
So$!region
A%A(collisions(! Direct!photon!
! Shape!engineering!
!
p(d)%A(collisions(! vn!measurement!

Sanshiro!Mizuno!
University!of!Tsukuba,!RIKEN!
06/06/2014!

A%A(collisions

postHQM!(so$)



Excess(of(Direct(Photon(Yield

0%20%

20%40%

40%60%
60%92%

External!photon!conversion!method!!
achieved!to!measure!0.4H5.0!GeV/c!!
and!several!centraliSes.!
Lower!pT!limit!is!extended.!
!
Enhancements!are!observed.!
!
!
It!is!found!that!the!shape!of!!
spectra!in!Au+Au!doesn’t!depend!!
on!centrality.

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

Non%Zero(Direct(Photon(v3gdirect (calorimeter)
gdirect (conversions)

v2

0.3

Au+AupRXP(I+O)
sNN = 200 GeV 
0.2 

0.1
0.0
0.15

0-20%

20-40%

40-60%

v3

0.10
0.05
0.00

012

3

40

1

23

pT [GeV/c]

401

2

3

4

NonHzero!posiSve!v3!is!observed!in!all!centrality,!as!seen!in!v2.!
Their!strengths!are!comparable!with!hadron.!
They!are!expected!to!constrain!photon!producSon!mechanism.!

postHQM!(so$)



Event(Shape(Engineering(1Q2,x =Q2,y =

X

X

wi cos(2 i )wi sin(2 i )qXq
Q2,raw = Q22,x + Q22,y /wiQ2 ⇠ Q2,raw / < Q2,raw >Q2!is!a!sort!of!the!strength!of!v2!and!!
selected!in!forward!rapidity.!
|η|!=!1~2.8!
ε2ini.(~(Q2(≈(v2(~(ε2ﬁn.((!
MulSplicity!and!iniSal!geometry!are!restricted!in!forward!rapidity!!
and!v2!and!ﬁnal!eccentricity!are!measured!in!midHrapidity.

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v2(and(ε2ﬁn.(in(mid%rapidity((|η|<0.35)

ε2ﬁnalv2!and!ﬁnal!eccentricity(ε2ﬁn.)!in!midHrapidity!are!changed!with!Q2!!
selecSon!in!forward!rapidity.!
!
High(Q2(%>(High(v2(&(High(ε2ﬁn.!HHH!High!ε2ini.?!

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

Event(Shape(Engineering(2

q2!is!observed!v2!in!FCal!(3.2<|η|<4.9).!
!
It!is!expected!to!reveal!hidden!iniSal!geometry!eﬀect.!

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vm%v2(Correla/on(Without(q2(selec/on
They!have!centrality!dependence.!

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v4%v2(correla/on(with(q2(selec/on

NonHlinear!correlaSon!is!found.
!
v4!is!divided!into!two!!
components!
• c0!:!independent!on!v2(ε2)!!
• c1!:!dependent!on!v2(ε2)!
!
They!are!extracted!by!ﬁhng.!

qv4 = c20 + c21 v24

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Non%Linear(&(Linear(v4(Componentqv4 = c20 + c21 v24

c0(:(Linear((ε4)(
c1(v22:(non%Linear((ε2)

In!central,!v4!is!uncorrelated!with!v2.!
Correlated!v4!gradually!increases!and!overtakes!at!around!Npart~120.!

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

p(d)%A(collisions

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

p(d)%A(Collisions
pPb!5.02TeV,!Ntrk!≥!110!
1<pT<3!GeV/c!

1 d2 N pairNtrg d ⌘d

PbPb!2.76TeV,!1<pT<1.5!GeV/c!
EPJC(2012)!72:2012

near!side!ridge
Long!range!nearHside!(Δφ!~!0)!ridge!have!been!observed!in!pPb.!
vn!components!are!extracted.!

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pPb!5.02TeV!
1<pT<3!GeV/c

Extrac/on(vn(componentNch≥220

Nch<20

YN,peakperi
YN,peakperi
YN,peak = ↵YN,peaksub
Y= Y{Nch 220} ↵Y{Nch <20}

Subtracted!yield!are!ﬁmed!by!Fourier!funcSon.

postHQM!(so$)



vn(2%5)(measurement(in(pPb• NonHzero!posiSve!vn!are!!
observed.!
• Rise!with!pT!at!low!pT!!
and!then!decrease,!!
it!is!similar!to!PbPb!collisions.
vn
P.R.C(86,(014907(2012)

pT(GeV/c)

postHQM!(so$)



Comparison(Npart(Dependencev2{2}

v3{2}

vn(in(PbPb(vn(in(pPb

Not!subtract!Ntrk<20!
0.3<pT<3!GeV/c!
|Δη|>2

Ntrk

Ntrk

There!are!deviaSon!in!v2!while!v3!are!comparable.!
Eccentricity!and!triangularity!study!are!needed.

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

v2(η)/v2(η=0)

η(Dependence(In(v2
Pb%going

p%goingηassocv2!in!PbHgoing!is!slightly!larger!than!v2!in!pHgoing.!
This!could!be!related!with!higher!parScle!densiSes.

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Collec/ve(Flow(In(pPb?
v2

pT(GeV/c)
Mass!ordering!is!observed!in!low!pT,!it!is!similar!to!the!trend!in!PbPb.!
Mesons!and!baryon!cross!at!about!2GeV/c.!
!
CollecSve!ﬂow!exists?!

postHQM!(so$)

 Collec/ve(Flow(In(dAu?C(Δφ)(:(CNT%Forward(Augoing)

v2

Δφ((rad)

Ridge!like!structure!is!seen!around!Δφ~0.!
Mass!ordering!is!observed!in!low!pT,!and!they!cross!at!around!2GeV/c.!
CollecSve!ﬂow!exists??!

postHQM!(so$)

 Mass(Ordering(In(v3??

It!is!observed!that!v3!has!mass!ordering!in!low!pT!and!they!cross!at!!
around!2.0!GeV/c.!
CollecSve!ﬂow!exists???!

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 Mass(ordering(in(pp???
Min.(Bias.

NonHﬂow!dominates!
measurement!
HH!No!ridge!observed.

Mass!ordering!is!observed!in!pp!collisions,!but!they!don’t!cross!as!it!is!!
found!in!PbPb!and!pPb!collisions.!
Mass!ordering!indicates!that!collecSve!ﬂow!exists????!

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Summary
A%A(collisions(• Direct!photon!study!
The!shape!of!yield!in!AuAu!doesn’t!depend!on!centrality.!
NonHzero!v3!is!observed.!
• Event!shape!engineering!
Q2!selecSon!helps!to!handle!event!selecSon.!
v4!is!divided!into!linear!and!nonHlinear!components.!
!
p(d)%A(collisions(Near!side!ridge!is!studied!by!measuring!vn.!
Npart,!η!and!parScle!species!dependence!are!measured.!
Mass!ordering!is!observed!in!pPb!and!dAu.!

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Other(Measurements
φ!v3!measurement!@STAR
/-Au+Au, 200GeV, 0%-80%

v3LPV!@STAR
d = ± 0.05
gap

-+0.1

Tkin(GeV)

/+Blast!Wave!ParameterizaSon!@ALICE

KKppq

q

0.05

01

2

30p (GeV/c)

123p (GeV/c)

T

<βT>

T

v1!in!CuAu!@PHENIX
v2!in!UU!@STAR

v1

0v1!in!pPb!@ATLAS

pT(Ge/c)

η

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postHQM!(so$)

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Direct(photon(Excess(Yield(Study
arXiv:1405.3940

DistribuSon!A$er!subtracSon!of!yield!in!!
scaled!pp!from!yield!in!AuAu

AeThe!amount!of!excess!direct!photon!yield

↵F = ANpart

pT /Tef f

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vm%q2(Correla/on

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v2((3(<pT<(4(GeV/c)

v2%v2(Correla/on(with(q2(selec/on
v2 ei2 2 / ✏2 ei2 2v2 ei2 2 = C✏2 ei2 2v2((0.5(<pT<(2(GeV/c)

NonHtrivial!dependence!with!centrality!(boomerang)!
Linear!dependence!within!one!centrality!
Indicates!that!viscous!correcSon!mostly!controlled!by!size,!not!shape.

postHQM!(so$)

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v3%v2(correla/on(with(q2(selec/on

v3 = kv2 + v30
v3!has!linear!and!anSHcorrelaSon!with!v2.!
These!measurement!can!constrain!iniSal!geometry!models.!

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 Mul/plicity(in(PbPb(and(pPb

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 

2PC(distribu/on
h(%(h

h(%(K

h(%(p

They!are!2PC!distribuSon!a$er!subtracSon!of!distribuSon!in!peripheral.!
The!region!in!|Δη|>0.8!are!ﬁmed!and!vn!are!extracted.

vnh {2P C} =qVnh hvni {2P C} = Vnh i

postHQM!(so$)

qVnh h