LHC−ALICE実験におけるソフトな指針で見るQGPQGP through soft probes at LHC-ALICE
江角晋一、 筑波大学、物理
ShinIchi Esumi, Univ. of Tsukuba

Contents
ALICE experiment at LHC
Multiplicity and pT distribution
HBT, v2 and higher harmonics vn
Multi-particle correlations
Summary
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

1Event display during my shift last November/2010

my shift leader

DAQ terminal

my PC

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

It was a nice winter day at CERN.
Univ. of Tsukuba, ShinIchi Esumi

2PID
TPC

V0T0

ZDC

A.Toia, QM11

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

3

Multiplicity in A+A at the highest possible energy
PRL105, 252301 (2010)

factor of ~2 increase with similar Npart dependence
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

4

dNch/dh distribution and ET/Nch

A.Toia, QM11

longitudinal scaling holds

increases with sqrt(sNN)

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

5Particle identified pT distribution

M.Floris, QM11

larger pT shift for heavier particles
larger radial flow than in this hydro model
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

6Particle mass and Npart dependence of <pT>

p+p
M.Floris, QM11

M.Floris, QM11

increased radial flow than at RHIC
and as a function of centrality
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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Blast wave fitting

Tch
QGP(hydro-dynamical model
based fitting function)p / p ratio

hadron gasµB

M.Floris, QM11

larger expansion at LHC
with similar freeze-out Tfo
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

M.Floris, QM11

Baryon density ~ 0
Univ. of Tsukuba, ShinIchi Esumi

8L)

Rlong
(R

beam

Rside (RTS)

HBT interferometry

Rout (RTO)
beam

duration time

22!" = R TO
# R TS/$expanding
sourcestatic source

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

9Similar kT dependence from extended andexpanding source

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

10Beam energy dependenceof 3D source size

factor of ~2 increasein source volume
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

11Elliptic flow (elliptic event anisotropy) : v2
lower pTxz
higher pT

Reaction planelarger energy loss
by long path lengthreaction planesmaller energy lossby short path length

Hydro-dynamical expansion

2nd harmonic amplitudeof azimuthal distribution
with respect to thereaction plane Φ2: v2

φitrack - Φnevent
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

12v2 vs pT comparison between RHIC and LHC

similar hydro-dynamic properties
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

13Beam energy dependence of <v2> and v2(pT)<v2> still increases with <pT>

v2(pT) saturates

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

14v2 and RAA at higher pT region

rtaintysystematic unce

R. Snellings, QM11

H. Appleshauser, QM11

v2 from suppression dominance given by path length
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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Particle identified v2 and RAA at higher pT

A. Dobrin, QM11

S. Schuchmann, QM11

particle dependence seems to be vanished at higher pT
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

16Particle identified v2 at lower pThydro (arXiv:1105.3226)

hydro (arXiv:1105.3226)

M. Krzewicki, QM11

larger mass-splitting + familiar Baryon/Meson difference
larger radial flow in central collisions than in this hydro model
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

17

Small deviations in (mT-m0)/nq scaled v2
Pb+Pb 2.76TeV

Au+Au 200GeV

Au+Au 39GeV

protonprotonPHENIX Preliminary

PHENIX Preliminary

M. Krzewicki, QM11

roughly (mT-m0)/nq scaled for all energies
larger pT shift for heavier particles
radial flow increases with energy
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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yv3 and Initial Fluctuation
Reaction Plane (x-z)

xx

arXiv:1003.0194zyy

black-disk--> sign-flipping v3
initial fluctuation --> no-sign-flipping v3
similar effects for all the higher moments vn
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, HirosakiUniv. of Tsukuba, ShinIchi Esumi

x19

Centrality and pT dependence of vnarXiv:1105.3865

almost zero signal for sign-flipping v3 (some small signal at RHIC-PHENIX)
significant non-sign-flipping v3, v4 at central and higher pT
smaller centrality dependence for v3, v4 than for v2
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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Particle identified v3
nq scalinghydro

M. Krzewicki, QM11hydro: similar mass-splitting at lower pT
nq scaling : similar Baryon / Meson difference at higher pT
The KET/nq scaling for v3 is also not as good as for v2
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

212-particle azimuthal correlation function
A. Adare, QM11--- flow un-subtracted C2 ---arXiv:1105.3865

rapidity separated C2 is well described by v2,3,4,5
as naturally expected because of vn{2, |Δη|>1}
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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(vntrig. x vnasso.) global fit
with various pT (trig. x asso.) combinations
describes the C2 shape well at lower pT(high pT x low pT) pairC2 is well described !

assumption : 2-part. correlationis only given by vn(pT)A. Adare, QM11

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

23vn{C2 global fit} ~ vn{2, |Δη|>1}

A. Adare, QM11

good agreement of vn even towards higher pTcoming from (low x high) pT combinations in C2JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

24init. fluc. : Glauber / CGC
hydro. η/s : Large / Small

arXiv:1105.3865
arXiv:1105.3928

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

25Summary
2.76TeV Pb+Pb collisions are measured in LHC-ALICE- factor of 2 in charged particle multiplicity dNch/dη
- factor of 2 in freeze-out volume from HBT- net-Baryron free region in the phase diagram- increased and pronounced radial flow in several cases- similar hydro properties compared with RHIC
- initial fluctuation and hydro-expansion drive the vn- discrimination power on initial geometry and viscosity

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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Back-up

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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PRC82.034913

K

arXiv:1104.0650

ε2ε3

ε4ε5ε2Gε3,ε5GK

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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arXiv:1108.1714

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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|Δη| dependence of vn from LHC-ATLAS
arXiv:1107.1468

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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|Δη| dependence of (vntrig. x vnasso.)with vn{C2 global fit}, which they call vn factorization in ATLAS

arXiv:1107.1468

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

31Probe the transverse geometry and/or dynamics
with trigger angle selected 2-particle correlation

thin side mach-cone(shoulder region)
φASSO-φTRIG>0near side(triggerdirection)

φASSO-φTRIG<0away side(head region)

thick side mach-cone(shoulder region)
φASSO-φTRIG<0

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

32jet, di-jet and multi-particle correlation with various conditions
ηJet , ηTrig.

φJet , φTrig.
8

φJet , φTrig.
1877654768654354
3
1

32

2

2
1

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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Observed left/right asymmetry remains
after “the usual/normal” v3 subtraction.
Trigger angle
selection w.r.t.
Φ2 separately
for left(up) /right(down)

out-of-plane
trigger case

Trig.

Trigger angle
selected 2-part.
corr. data areplotted in polar
coordinate byrotating Φ2 R.P.
angle as X-axis.
Flow subtracted
yield is shown
radially with baseline.

Trig.

in-planetrigger case

200GeV Au+Au -> h-h(pTTrig=2~4, pTAsso=1~2GeV/c)v2(v4{Φ2})-only subtraction
PHENIX preliminary

Φ2 R.P.

Φ2 R.P.

Trig.
Trig.

surface dominancepenetration dominanceTwo competing processes seen
JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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Possible charge asymmetry signal
from Local Parity Violation
S. A. Voloshin, Phys. Rev. C 70, 057901 (2004).

STAR Collaboration: Phys. Rev. Lett. 81, 251601 (2009)STAR Collaboration: Phys. Rev. C81, 054908 (2010)

P. Christakoglou, QM11

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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pT dependence of theobserved asymmetry signal

P. Christakoglou, QM11

JPS symposium, QGP at RHIC-LHC, 17/Sep/2011, Hirosaki

Univ. of Tsukuba, ShinIchi Esumi

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