Recent (and some old) Resultsfrom PHENIX (and RHIC, LHC)
ShinIchi Esumi
Inst. of Physics
Univ. of Tsukuba

Contents
Bulk properties (Soft) : collective expansion effects
Energy loss (Hard) : high pT / jet suppressions
Soft / Hard interplay : jet / bulk modification

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba1

SQM06, Yifei Zhang

Radial expansion--- freeze-out time dependence ---AuAu Central
charm hadron

AuAu Central
strangeness hadrontfuooyerzoteseifrHnorhad
SQM06, Yifei Zhang

ATHIC2010, 18/Oct/2010, Wuhan, China

AuAu Centralπ, K, p

ShinIchi Esumi, Univ. of Tsukuba

2

Quark momentum distribution--- extracted from multi-strange hadron ratio --arXiv:0801.2265 [nucl-th]

dquar
k

squar
k

Hadron

d-q
uar
ks-q
uar
k

Collective radial expansion-during the partonic phase-before the hadronic phase
Quark coalescence orrecombination mechanism
for the hadronization

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

3

HadronPartonic collectivity--- particle identified v2 --Number of constituent quark scalingin hadron v2 as well as multi-strange
baryon v2: v2 is already establishedduring the quark phase before thehadronization. This seems to be true
even for heavy quark like charm.

QM08: A.Dion
QM06

STAR preliminary

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

4

Higher order anisotropy v4 vs v2

PRL105, 062301 (2010)--- relation with hydro expansion --v2 > 0v2 < 0ATHIC2010, 18/Oct/2010, Wuhan, China

v4 > 0v4 < 0

ShinIchi Esumi, Univ. of Tsukuba

5

Parity violation signal--- charge asymmetry w.r.t. R.P. ---L or B

Fuqiang Wang,
this morning

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

6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

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

7

Particle species dependence of suppression (RAA)--- some quark flavor difference? ---ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba8

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 .
Jiangyong Jia,
this afternoon

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

9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

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

10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: STARATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

11

QM09: PHENIX

c2(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 selectionaverage(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)ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

12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

ATHIC2010, 18/Oct/2010, Wuhan, China

Trigger angle

PHENIX preliminary

ShinIchi Esumi, Univ. of Tsukuba

13

nothing left?

nothing left?

Hard Probe 2010, G. Roland

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

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

14

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 seen
at 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

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

15

Hard Probe 2010, Yue Shi Lai

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

to yres nergolecnd rtonar
ser ial paolge
C initgitrathemmaerGggi) tr
Rrgeal(Jeterggtri)ll Ra(smteJergig) tr
ndroaiasb0 (hπacefr
su serolosmydg
an enerer
mo en bygiv

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

16

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

D-CAL upgrade
ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba17γ-Triggered Away-side Correlations:
Jet Fragmentation Function in p+p and Au+Au

total jet energy
is carried by γ

QM09 PHENIX

softn

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

dN! bz= Ne T
dzTzT = pTh / pT"

ATHIC2010, 18/Oct/2010, Wuhan, China!

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

ShinIchi Esumi, Univ. of Tsukuba

18

Direct photon at low pT--- path to the initial temperature ----- thermal photon radiation from QGP ----- v2 of these photons for further tests ---prompt photon production from initial binary collisions can explain themeasured direct photon spectra at p+p and d+Au for entire pT region
and also at Au+Au for high pT region, however not at mid-central tocentral Au+Au collisions especially for lower pT region below 3GeV/c

ATHIC2010, 18/Oct/2010, Wuhan, China

PRL104, 132301
arXiv:0804.4168v1

Slope parameter (0-20%):
T = (221 ± 23 ± 18) MeVVarious Hydro models:
TInitial = 300~600 MeV
ShinIchi Esumi, Univ. of Tsukuba

19Summary* Transverse momentum distribution --- radial flow
* Elliptic and higher order event anisotropy --- elliptic flow
* Charge asymmetry --- possible parity violation* High pT/jet suppression RAA and v2 --- energy loss
* Jet modification via correlation --- feed back to bulk property* Ridge, Mach-cone like structure vs triangular anisotropy* Controlled biases with direct photon, jet and single hadron* Initial temperature with thermal photon (and lepton pairs…)

ATHIC2010, 18/Oct/2010, Wuhan, China

ShinIchi Esumi, Univ. of Tsukuba

20

ATHIC2008
in Tsukuba,S. Esumi

trigger
IAPY 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).

ATHIC2010, 18/Oct/2010, Wuhan, ChinaΔη

ShinIchi Esumi, Univ. of Tsukuba)Δφ(rad21