20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 1

Rapporteur 3

Bulk Properties and Collective Phenomena

ShinIchi EsumiUniv. of Tsukuba

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 2

dn/dy, spectra, chemical/thermal freeze-outstopping, radial flow, recombinationHBT, global polarizationrapidity dependence

eccentricity definitionevent by event v2 fluctuationv1 and v2 scaling

jet and its correlation with v2

charm quark interaction and collectivitydirect photon as a probe of bulk matter

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 3

‘net

’ pro

ton

dN/d

y

AGS

SPS

RHIC 62

RHIC 200

LHC 5500

(BRAHMS preliminary)

NA49 preliminary

baryon transport (stopping)

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 4

STAR Preliminary

STAR Preliminary

hadron spectra after strong radial expansion

STAR (sNN=130 GeV)

mass [GeV/c2]Inve

rse

slop

e pa

ram

eter

[G

eV/c

2 ]

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 5

STAR Preliminary

5% central10% centralMin-Bias

Kp thermal fit

BRAHMS

BRAHMS

hadron production at chemical freeze-out close to the phase boundary

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 6

p/

p/

baryon transport + radial flow + recombination + jet suppression

Au+Au 200GeVSTAR preliminary

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 7

mT (GeV/c)

Rin

v (

fm)

STAR preliminary

HBT freeze-out is given by energy density. strong effect from collective expansion and space-time correlation. reconstruct source image without assuming the source shape

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 8

global polarizationLambda polarization w.r.t. (normal to) directed event planeno significant signal observed, upper limit : |P,|~10-2

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 9

y=0 y=1 y=3.1

pions

kaons

protons

rapidity dependence of identified particle nuclear suppression

No strong indication of rapidity dependence

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 10

=0 ≈3

K

p

rapidity dependence of identified particle v2

BRAHMS preliminary

No strong indication of rapidity dependence, the strong rapidity dependence on the integrated v2 is more or less explained by the mean pT. Meson/baryon splitting might be different between y=0 and y=3, if statistical significance is improved.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 11

Participant EccentricityStandard Eccentricity 200 GeV200 GeV

arXiv:nucl-ex/0610037, submitted to PRL

Cu+Cu

Au+Au

Cu+Cu

Au+Au

eccentricity definition

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 12

v2 scales with <part> and energy densidy

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 13

PHOBOS part prediction

MC with nofluctuations

event by event v2 fluctuation vs part fluctuation

This relative v2 fluctuation can be explained by initial part fluctuation…

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 14

All participant positions are used to define a new axis and to get eccentricity simultaneously in the new rotated axis.We try to remove a particle from reaction plane definition to avoid auto-correlation between particle and event plane, when measuring v2 of the particle.

(1) exclude one participant to define a new frame(2) calculate position of the excluded participant in the new frame(3) repeat above 2 steps for all participants(4) get eccentricity using positions of all participantsEach participant position is defined in its own frame. If particles are generated from position of participants, it is more natural to get eccentricity in this way.I would not say this is the best, just like to say there is still a room for improvements.

STD PART MOD

participant modified participant

Cu+CuAu+Au

impact parameter : b (fm)

x (fm)

impact parameter : b (fm)

y (f

m)

eccentricity re-visited

ParticipantModifiedStandard

v2

= ?

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 15

part 0-5% 1.5/0.9 = 1.7 5-10% 1.7/1.1 = 1.5experiment Cu/Au v2 ratiophobos 2.6/1.5 = 1.7 3.1/2.1 = 1.5star v2{2}0-5% 3.7/2.5 = 1.5 5-10% 4.2/3.5 = 1.2star v2{ftpc} 0-5 3.0/2.1 = 1.4 5-10 3.4/3.4 = 1.0phenix 0-10% 4.0/3.0 = 1.3

STAR

centrality dependence of v2

comparison of v2 ratio : Cu+Cu/Au+Au (>1) at central (<10%) collisions between experiments

PHENIX PRELIMINARY

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 16

STAR 200GeV Au+Au 20-60%

PHENIX 200GeV Cu+CuSTAR 200GeV Cu+Cu 20-60%

PHOBOS 200GeV Cu+Cu 20-40%

PHOBOS 200GeV Au+Au 20-40%

V2{2}V2{FTPC}V2{AA-pp}

V2{2}V2{FTPC} V2{4}

PHENIX 200GeV Au+Au 30-40%

V2{BBC R.P.}

STAR FTPC and PHENIX BBC have about same acceptance.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 17

v1 scaling w.r.t. beam rapidity and v1 wiggle (proton)

Centrality scaling for v1 seems to work better than participant scaling which works for the most of other global variables. This might be trivial if this is only given by participant/spectator shape alone not by the size at all…

STAR preliminary

STAR preliminary

spectator v1 direction

anti-flow of p as seen in SPS

Different trend could be caused by the different pT cut off.

PHOBOS

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 18

v2 scaling with mT-m + number of quark(same as hydro at low pT + number of quark)

When the mass effect removed by mT-m, only the quark number ratio shows up! Is mass ordering of v2 at low pT generated during or after hadronization?Feed-down for pion is visible in pT, but not in mT-m, because pT(daughter) < pT(parent) , but mT-m(daughter) ~ mT-m(parent) …Decay kinematical effect is masked by the pT to mT-m transformation.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 19

STAR preliminary

v2 scaling with mT-m + number of quark

v2

pT (GeV/c)

RQMD Au+Au 200GeV

Feng Liu

Number of quark scaling is not only the explanation.

Early freeze-out effect of multi-strangeness hadrons seen in spectra analysis with radial flow does not show up here in v2 analysis, this is an indication that v2 is already built up in early stage.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 20

STARpreliminary

0-12% 200 GeV Au+Au

PHENIX nucl-ex/0611019

PHENIX Preliminary10-20% Au+Au 200GeVpT

trig=2.5-4 GeV/c pT

assoc=1-2.5 GeV/c

STAR preliminary0-12% Au+Au 200GeVpT

trig=3-4 GeV/c pT

assoc=1-2 GeV/c

CERES preliminary

0-5% Pb +Au 17GeV pT

trig=2.5-4 GeV/c pT

assoc=1-2.5 GeV/c

CERES preliminary0-5% Pb +Au 17GeV pT

trig=2.5-4 GeV/c pT

assoc=1-2.5 GeV/c

jet modification and cone like structure

The bulk and jet interaction is there, but in Cu+Cu/Au+Au and SPS-RHIC?!?

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 21

STAR, PRL93 (2004) 252301.

|trig-RP|

PHENIX, nucl-ex/0510019.

jet modification and its correlation with v2

jet shape w.r.t. reaction plane geometrical effect of the almond shapeThis effect itself is a one of v2 sources,which will be an important effect at LHC.This should also lead different v2 between bulk and jet.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 22

charm quark suppression and flow

Charm quark interaction in bulk matter, this makes suppression and collectivity of charm quarks as well as light quarks.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 23

N. Xu, SQM 2006, PHENIX (, K, p, J/): PRC69, 034909(04), QM05; STAR (, , ): QM05

AuAu Central charm hadron

AuAu Central , K, p

AuAu Central strangeness hadron

SQM06, Yifei Zhang

RHIC

SPS SPS

more hints of charm quark collectivity

PHENIX J/

PBM et. al. QM06

J/ would need re-generation, both J/ and open charm spectra are consistent with small transverse radial flow, which might be built up during partonic stage…

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 24

PHENIX preliminary

annihilationcompton scattering

Bremsstrahlung (energy loss)prompt photon v2 = 0

v2 < 0thermal photon v2 > 0

Jet-frag. photon from the survived partonv2 > 0

Inclusive photon v2 presented by STAR

direct photon as a probe of bulk matter

consistent with prompt photon production,

but we are allowed to speculate, I guess…

We just have installed a new reaction plane detector for coming high

luminosity Au+Au run7 for rare probe v2 measurement at PHENIX.

20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba 25

Summary

Large number of variables indicate as if there is Quark Gluon Plasma formed at RHIC energies or maybe already at lower energies, however the most of the evidences are still only suggestive, can we look for more direct evidence?