1. Bulk Properties and Collective Phenomena
Rapporteur 3
Bulk Properties and Collective Phenomena
ShinIchi Esumi
Univ. of Tsukuba
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

2. ShinIchi Esumi, Univ. of Tsukuba
dn/dy, spectra, chemical/thermal freeze-out
stopping, radial flow, recombination
HBT, global polarization
rapidity dependence
eccentricity definition
event by event v2 fluctuation
v1 and v2 scaling
jet and its correlation with v2
charm quark interaction and collectivity
direct photon as a probe of bulk matter
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

3. ShinIchi Esumi, Univ. of Tsukuba
baryon transport (stopping)
AGS
NA49
preliminary
SPS
RHIC 62
‘net’ proton dN/dy
(BRAHMS preliminary)
RHIC 200
LHC 5500
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

4. hadron spectra after strong radial expansion
STAR Preliminary
STAR Preliminary
STAR (sNN=130 GeV)
mass [GeV/c2]
Inverse slope parameter [GeV/c2]
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

5. ShinIchi Esumi, Univ. of Tsukuba
hadron production at chemical freeze-out close to the phase boundary
BRAHMS
BRAHMS
STAR Preliminary
5% central
10% central
Min-Bias
Kp thermal fit
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

6. ShinIchi Esumi, Univ. of Tsukuba
baryon transport + radial flow + recombination + jet suppression
p/-
p/+
Au+Au 200GeV
STAR preliminary
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

7. ShinIchi Esumi, Univ. of Tsukuba
mT (GeV/c)
Rinv (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. ShinIchi Esumi, Univ. of Tsukuba
global polarization
Lambda polarization w.r.t. (normal to) directed event plane
no significant signal observed, upper limit : |PL,L|~10-2
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

9. ShinIchi Esumi, Univ. of Tsukuba
rapidity dependence of identified particle nuclear suppression
y=0
y=1
y=3.1
pions
kaons
protons
No strong indication of rapidity dependence
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

10. ShinIchi Esumi, Univ. of Tsukuba
rapidity dependence of identified particle v2
=0
≈3
BRAHMS preliminary  K p
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. eccentricity definition
Standard Eccentricity
Participant Eccentricity
200 GeV
200 GeV
Cu+Cu
Cu+Cu
Au+Au
Au+Au
arXiv:nucl-ex/ , submitted to PRL
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

12. ShinIchi Esumi, Univ. of Tsukuba
v2 scales with <epart>
and energy densidy
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

13. event by event v2 fluctuation vs epart fluctuation
PHOBOS epart prediction
This relative v2 fluctuation can be explained by initial epart fluctuation…
MC with no fluctuations
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

14. ShinIchi Esumi, Univ. of Tsukuba
eccentricity re-visited
participant e
modified participant e v2 e = ?
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 participants
Each 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.
eSTD
ePART
eMOD e e
Au+Au
Cu+Cu
y (fm)
Participant
Modified
Standard
x (fm) e
impact parameter : b (fm)
impact parameter : b (fm)
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

15. ShinIchi Esumi, Univ. of Tsukuba
centrality dependence of v2
comparison of v2 ratio : Cu+Cu/Au+Au (>1) at central (<10%) collisions between experiments
STAR
PHENIX PRELIMINARY
epart 0-5% /0.9 = 1.7
5-10% /1.1 = 1.5
experiment Cu/Au v2 ratio
phobos /1.5 = 1.7
3.1/2.1 = 1.5
star v2{2}0-5% /2.5 = 1.5
5-10% /3.5 = 1.2
star v2{ftpc} /2.1 = 1.4
/3.4 = 1.0
phenix 0-10% /3.0 = 1.3
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

16. ShinIchi Esumi, Univ. of Tsukuba
V2{FTPC}
- V2{4}
V2{BBC R.P.}
STAR 200GeV Au+Au
20-60%
PHENIX 200GeV Au+Au
30-40%
PHOBOS 200GeV Au+Au
20-40%
STAR FTPC and PHENIX BBC
have about same acceptance.
V2{2}
V2{FTPC}
V2{AA-pp}
PHOBOS 200GeV Cu+Cu
20-40%
STAR 200GeV Cu+Cu
20-60%
PHENIX 200GeV Cu+Cu
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

17. ShinIchi Esumi, Univ. of Tsukuba
v1 scaling w.r.t. beam rapidity and v1 wiggle (proton)
STAR preliminary
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…
spectator v1
direction
Different trend could be caused by the different pT cut off.
anti-flow of p as seen in SPS
STAR preliminary
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. v2 scaling with mT-m + number of quark
STAR preliminary
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.
Number of quark scaling is not only the explanation.
RQMD Au+Au 200GeV
Feng Liu v2
pT (GeV/c)
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba

20. jet modification and cone like structure
STAR
preliminary
0-5% Pb +Au 17GeV pTtrig=2.5-4 GeV/c pTassoc=1-2.5 GeV/c
PHENIX
nucl-ex/
0-12% 200 GeV Au+Au
CERES preliminary
PHENIX Preliminary
10-20% Au+Au 200GeV
pTtrig=2.5-4 GeV/c
pTassoc=1-2.5 GeV/c
STAR preliminary
0-12% Au+Au 200GeV
pTtrig=3-4 GeV/c
pTassoc=1-2 GeV/c
CERES preliminary 0-5% Pb +Au 17GeV pTtrig=2.5-4 GeV/c pTassoc=1-2.5 GeV/c
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. jet modification and its correlation with v2
STAR, PRL93 (2004)
PHENIX, nucl-ex/
|ftrig-fRP|
jet shape w.r.t. reaction plane
geometrical effect of the almond shape
This 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. more hints of charm quark collectivity
N. Xu, SQM 2006, PHENIX (, K, p, J/): PRC69, (04), QM05; STAR (, , ): QM05
PBM et. al. QM06
PHENIX J/y
RHIC
SPS
SPS
AuAu Central charm hadron
AuAu Central , K, p
AuAu Central strangeness hadron
SQM06, Yifei Zhang
J/y would need re-generation, both J/y 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. direct photon as a probe of bulk matter
annihilation
compton scattering
Bremsstrahlung
(energy loss)
Jet-frag. photon from the survived parton
v2 > 0
thermal photon v2 > 0
prompt photon v2 = 0
v2 < 0
Inclusive photon v2 presented by STAR
consistent with prompt photon production,
but we are allowed to speculate, I guess…
PHENIX preliminary
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. ShinIchi Esumi, Univ. of Tsukuba
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?
20 Nov 2006, Quark Matter, Shanghai, China
ShinIchi Esumi, Univ. of Tsukuba