1. ShinIchi Esumi, Univ. of Tsukuba
Event anisotropy in high-energy heavy-ion
collisions at RHIC
ShinIchi Esumi
Inst. of Physics, Univ. of Tsukuba
elliptic flow and nuclear suppression factor
identified hadron v2
f v2/RAA(quark coalescence or hydro)
electron v2/RAA(charm quark)
inclusive g, p0 v2 (direct g v2/RAA)
e (eccentricity) scaling
jet correlation and v2
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

2. ShinIchi Esumi, Univ. of Tsukubax z
Non-central Collisions
initial collision geometry
pressure/density gradient,
radial/elliptic expansion
final momentum anisotropy y x
reaction plane
angle : n
2nd harmonic
amplitude : v2
Σ wi*sin(ni)
tan(nn) =
Σ wi*cos(ni)
|fi-n|
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

3. ShinIchi Esumi, Univ. of Tsukubay x b
yield (A+A)
RAA , RCP
relative yield in A+A
collisions normalized by
p+p yield times number of
binary collisions
R AA =
<Ncoll> yield (p+p)
yieldCentral / <Ncoll>Central
R CP =
yieldPeripheral / <Ncoll>Periheral
Npart : number of participant
participant scaling
Ncoll : number of binary collision
binary scaling x z
2x1=2
3x2=6
3x3=9
1x2=2
impact
parameter : b
total 30 collisions
total 23 participant nucleons
spectators
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

4. ShinIchi Esumi, Univ. of Tsukuba
spectator directed R.P.
Reaction plane detectors
MVD
SMD/ZDC
BBC
participant elliptic R.P.
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

5. ShinIchi Esumi, Univ. of Tsukuba
FBBC1-p vs FBBC2
FSMD1-p vs FSMD2
FSMD-p vs FBBC
back-to-back
back-to-back
spectator neutrons vs
ps from participants
are flowing opposite.
directed
plane
beam line
reaction plane
neutron spectator
charged particles
(pions) at mid h
beam
[-p,p]
F2BBC1 vs F2BBC2
F2MVD1 vs F2MVD2
F2BBC vs F2MVD
elliptic
plane
[-p/2,p/2]
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

6. ShinIchi Esumi, Univ. of Tsukuba
Identified hadron v2
hydro dynamic behavior at low pT
baryon/meson difference at high pT
QM05 PHENIX
QM05 STAR
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

7. ShinIchi Esumi, Univ. of Tsukuba
f-meson v2
mass scaling or number of quark scaling? baryon/meson (number of quark) difference hydro dynamic behavior : mf-meson ~ mproton early hadronic freeze-out for multi-strangeness hadrons _
Ξ+Ξ
Ω+Ω  _
QM05 PHENIX
QM05 STAR
need more data/beam
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

8. ShinIchi Esumi, Univ. of Tsukuba
Nuclear modification factor : RCP
clear separation between baryon group / meson group
including f,W,X as well as p,K,p
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

9. ShinIchi Esumi, Univ. of Tsukuba
Number of quark scaling of v2
rather good description above 1GeV/c in quark pT
remaining mass dependence at lower pT region
v2 is already formed during quark phase before hadronization
additional hadronic flow might be there after hadronization
QM05 PHENIX
QM05 STAR
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

10. ShinIchi Esumi, Univ. of Tsukuba
Non-photonic electron (charm origin) RAA compared with p0 RAA
Non-photonic electron is less suppressed compared
with p0, but it is still a significant suppression
RAA~ 0.3 at higher pT region 4~5GeV/c
non-photonic electron v2 is similar with other hadrons at low pT but smaller at higher pT region 4~5GeV/c
photonic electron v2 originated from p0 is above p0 v2 at low pT and similar to p0 v2 at high pT and subtracted already.
(1) q_hat = 0 GeV2/fm
(4) dNg / dy = 1000
(2) q_hat = 4 GeV2/fm
(3) q_hat = 14 GeV2/fm
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

11. ShinIchi Esumi, Univ. of Tsukuba
non-photonic electron : charm (+beauty) RAA and v2
very significant suppression at higher pT some difference between experiments at higher pT
almost same as p0 suppression above 5GeV/c which needs to be solved.
D-meson flows (+ve v2), should determine charm v2
B. Zhang et al.
nucl-th/
b contribution
less suppression
less interaction
b contribution
less flow
less thermalized
I’m very much looking forward to hearing following electron v2 talks!!
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

12. ShinIchi Esumi, Univ. of Tsukuba
Direct photons are not suppressed
RAA is about 1.0 high pT, g/p0 ratio > 1 at high pT
Direct photon contribution is significant at high pT and at
central collisions compared to the inclusive photon yield
from the known hadronic sources.
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

13. ShinIchi Esumi, Univ. of Tsukuba
inclusive g and p0 v2
v2 of direct photon gives complimentary information in understanding the origin of binary scaled direct photon production.
Bresmsrahlung,
because of larger
energy loss
v2 < 0
fragmentation in vacuum, from escaped parton v2 > 0
nucl-ex/
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

14. ShinIchi Esumi, Univ. of Tsukuba
try to extract direct g v2
v2direct g =
R v2inclusive g – v2b.g.
R – 1
R =
v2inclusive g
v2b.g
if v2direct g = 0
v2b.g. : expected g v2 from hadronic decays
nucl-ex/
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

15. ShinIchi Esumi, Univ. of Tsukuba
inclusive g and p0 v2
QM05 : Phenix preliminary run4 v2
0-10 %
10-20 % p0
inclusive g
20-30 %
30-40 %
40-50 %
50-60 %
pT (GeV/c)
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

16. ShinIchi Esumi, Univ. of Tsukuba
Low pT direct g can be extracted
in a different way for
both pT distribution and v2.
better accuracy at low pT might be expected.
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

17. ShinIchi Esumi, Univ. of Tsukuba
dNch/dh scales with Npart for both Au+Au / Cu+Cu
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

18. ShinIchi Esumi, Univ. of Tsukuba
RAA scales with Npart for both Au+Au / Cu+Cu
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

19. v2 does NOT scale with Npart for obvious reason ----- Geometry -----
<v2> (|h|<2)
true R.P.
participant R.P.
RQMDv2.4
with true R.P.
black : Au+Au
red : Cu+Cu
if use all participants to define its axis and its deformation,
maximum auto-correlation in e definition?
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

20. ShinIchi Esumi, Univ. of Tsukuba
Participant eccentricity includes initial statistical fluctuation of e and its axis, while experimental v2 and reaction plane (from participants with the 2nd moment axis) includes all fluctuations until final particle productions.
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

21. ShinIchi Esumi, Univ. of Tsukuba
Lesson from PHOBOS should also be considered when comparing between experiments especially for light system.
The difference between 2nd and 4th order cumulant results differ especially for Cu+Cu.
QM05 PHENIX
QM05 STAR
238U + 238U
Si + Au
Npart. scaling
Ncoll. scaling
eecc. scaling
Au+Au
Cu+Cu
Si(Cu)+Au
v2 RAA
jet/HBT(R.P.)
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

22. ShinIchi Esumi, Univ. of Tsukuba
1st moment R.P. (SMD/ZDC, BBC, FTPC)
e of participant with axis from spectator :
yet another e needed?
Cu+Cu w.r.t. SMD/ZDC (spectator directed) R.P. needed,
it can be different with participant elliptic R.P.
ZDC/SMD　
spectator v1
Au +Au 200 GeV
QM05 PHOBOS
spectator directed R.P.
STAR preliminary
QM05 STAR
participant elliptic R.P.
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

23. ShinIchi Esumi, Univ. of Tsukuba
We should not forget that hadronic cascade can generate apparent number of quark scaling without quark coalescence, although the magnitude of v2 is about a half of experimental data.
ISMD 2005
UrQMD
origin of this apparent scaling needs to be understood
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

24. ShinIchi Esumi, Univ. of Tsukuba
High pT away-side jet suppression
softening of associated pT distribution
modification of jet shape at mid-pT
QM05 : Phenix preliminary
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

25. ShinIchi Esumi, Univ. of Tsukuba
re-appearance (escaped) of high pT back-to-back jet pT
pT(assoc) > 2 GeV/c pT
Au+Au, 0-5%
STAR Preliminary
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

26. re-appearance (escaped) of high pT back-to-back jet
centrality
PHENIX Preliminary
STAR Preliminary
8 < pT(trig) < 15 GeV/c
pT(assoc)>6 GeV
system/centrality
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

27. ShinIchi Esumi, Univ. of Tsukuba
PHENIX preliminary
jet shape w.r.t. R.P.
source of v2 at high pT
v4 effects need to be considered
jet v2 = b.g.(thermal) v2
extract jet shape or jet v2
in-plane pair
in between pair
out-of-plane pair
jet yield (a.u.)
pTtrigger(h) > 3GeV/c
1< pTassociated(h) <2GeV/c
PHENIX preliminary
　　　　　　 p
Df (rad)
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

28. ShinIchi Esumi, Univ. of Tsukuba
RAA v2
proton pion electron photon pT 1
0.1
|Df| p
jet shape
Summary
identified particles, f, e+-, g v2
* partonic flow ?
* heavy quark v2 ?
* direct photon production ?
Npart. , Ncoll. , eecc.scaling
* test with asymmetric collisions ?
jet correlation and v2
* jet shape w.r.t. R.P. or jet v2 ?
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

29. ShinIchi Esumi, Univ. of Tsukuba
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba

30. ShinIchi Esumi, Univ. of Tsukuba
JPS/DNP 2005 Sep. Maui
ShinIchi Esumi, Univ. of Tsukuba