ismd31 / sept. 4, 2001 toru sugitate / hiroshima univ. the 31 st international symposium on...
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Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
The 31st International Symposium onMultiparticle Dynamicson 1-7, Sept. 2001
in Datong, China
Correlation and fluctuation studies at RHIC
Toru Sugitate Hiroshima University
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Multiparticle dynamics in high-energy heavy-ion collisions
Relativistic Heavy Ion Collider (RHIC) begins smashing atoms at sNN = 200 GeV.
Experiments will yield insights into the structure of matter and how the universe evolved.
Understand the non-pertuabative QCD nature; multiparticle dynamics of deconfined quarks and gluons in Quark-Gluon-Plasma, which probably existed in the early Universe.
Te
mp
era
tur
e
Baryon densityNormalNucleus
Hadronic Matter
Quark-Gluon Plasma
quark confinement
Chiral symmetry
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
222TO
2TO
2TS
2TS
2L
2L2 RqRqRqexp1C
expTOR
In the Longitudinal Center of Mass System (p1z+p2
z=0);
2expTS
2expTO
22pair RR
It is obvious for a static source, but our source is expanding..
2
2
2TO
2TO
2TS
2TS
2L
2L
2
t
R2
r
R2
r
R2
rexpt,r
Particle correlations – a tool to pin down the phase transition
In the 1st order phase transition, matter of the mixed phases stops expansion due to the softening of Equation of State.
Consequently a prolonged lifetime of particle emission is expected.
T
B
TC
QGP
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
The STAR (Solenoidal Tracker at RHIC) experiment at RHIC
K p d
e
STAR STAR AcceptancAcceptanc
ee
A large volume TPC covers || < 1 with a full azimuthal coverage.
PID capability of TPC - dE/dx and RICH. Topological PID technique for short lived and/or ne
utral particles.
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
The PHENIX (Pioneering High Energy Nuclear Interaction eXperiment) at RHIC
Broadest possible study of A-A, p-A, p-p collisions tostudy nuclear matter under extreme conditions using a wide
variety of probes sensitive to all timescales, i.e., hadrons, electron, muons, and photons as many potential signatures of QGP as possible, and
study systematic variations with species and energy. Measure spin structure of the nucleon.
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Negative pion correlation studies in STAR and PHENIX
STAR published in PRL 87(2001)082301
PHENIX preliminary for QM01
Q (
MeV/c)
Q Long
Q ( MeV/
c)
Q ( MeV/
c)
Q Side Q Out
C 2 (Q
; Qot
hers<
80 M
eV/c
)First particle correlation data at RHIC. Consistent between two experiments. Positive pions show similar results.No surprise with the C2 functions.
12-15% most central events in Au+Au at sNN=130 GeV.Negative pions in the mid-rapidity.3 dimensional analysis in the LCMS frame.
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
s dependence of source size parameters viewed by negative pions
No significant rise or jump from AGS to RHIC. Parameters are quite similar to those at SPS.Transverse radii seems to be constant.Longitudinal radius increases as s.
sNN (GeV)
101 100
Rou
t/Rsi
de
0
1.5
0.5
1
4
2
(R
out2 -R
side
2 )
E895 NA44 NA49 PHENIXE866 WA98 STAR
sNN (GeV)101 100
Rou
t (fm
)R
side
(fm
)
8
4
6
8
4
6
8
4
6
2
1
0.4
0.8
1.2
0.6
Rlo
ng (f
m)
No remarkable difference between Rout and Rside. is similar to those at SPS/AGS.No indication of a long-lived mixed phase.
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Centrality and mT dependences of the source size parameter
STAR published data in PRL87 (2001)082301
1.0
0.4
0.8
1.2
0.6
+ -
0.2med highlowcentrality bin mT (GeV/c2)
0.3 0.4
Rou
t (fm
) 8
4
6
Rsi
de (f
m) 8
4
6
8
4
6
2
Rlo
ng (f
m)
+ and - show same dependences.’s do not change with multiplicity, but R’s increase with centrality.
consistent with native expectation of geometrical size.
’s increase, but R’s decrease as mT. consistent with a hypothesis of hydrodyna
mical expanding sources.
NA44 published in PRL 87(2001)112301
R=3.0 / mT
+ -
0.2med highlowcentrality bin mT (GeV/c2)
0.3 0.4
Rou
t (fm
) 8
4
6
Rsi
de (f
m) 8
4
6
8
4
6
2
Rlo
ng (f
m)
Does the mT scaling observed at SPS explain the present RTrans and RLong data at RHIC ?
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Fluctuations – a tool to pin down the phase transition
Fluctuation of locally conserved quantities; net baryon number, electric charge, strangeness prove the quark de-confinement phase.
O
OOO T)(222
T)(
T)(
Tre
eTrO
OOO
H
H
014.0S/)N(
033.0S/)N(2QGP
b
2HGb
036.0S/)Q(
06.0S/)Q(2QGP
2HG
The Net Baryon number in hadron gas
)Tcosh()0,T(N2)N(
e)0,T(N),T(N
b2HGb
Tbb
The net Baryon number in a QGP with 2 massless flavor
2
32QGPb T3
11T
9
2)N(
V
1
M. Asakawa presented in QM01;
Then, we should see difference in;
and
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Event-by-event fluctuations in the mean Pt in PHENIX
Centrality: 0-5%
PHENIX Preliminary
<Pt> (GeV/c)
Data vs. Mixed Event <Pt> (GeV/c)
<Pt> , Central Collisions
Note: This is not a fit!
by J. Mitchell (BNL) for the ACS on 8/30/01
Gamma Distribution Calculation
M. Tannenbaum, Phys. Lett. B498 (2001) 29.
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Event-by-event fluctuations in the mean Et in PHENIX
Mean Max Simulation Centrality: 0-5%
PHENIX Preliminary
PbSc <Et> (GeV)
<Et> , Central Collisions
by J. Mitchell (BNL) for the ACS on 8/30/01
Simulation for statistically independent emission incl. experimental biases.
Toru Sugitate / Hiroshima Univ. ISMD31 / Sept. 4, 2001
Summary and outlook of correlation and fluctuation studies at RHIC
The source size parameters at sNN = 130 GeV are similar to those at SPS/AGS. The duration time is consistent with zero, similar to those at SPS/AGS. No indications of a huge source formation or a prolonged mixed phase. No significant non-statistical fluctuations in <pT> and <ET> were seen by PHENIX, b
ut some indication in charge independent <pT> by STAR.
Why all the source sizes are almost constant in about two orders of s? No QGP’s? What controls the source size parameters?
Why the mT scaling at SPS explains the radii at RHIC? Is there any universal scaling on s? Another hint; RLong ~ RTrans at both SPS and RHIC.
Why almost no duration time during pion emissions? Did hydrodynamical flow wash out the signals?
Look at Au+Au at sNN = 200 GeV. Study the correlation functions by other particle species. Study the net baryon-, charge- and strangenss-fluctuations. Event-by-Event correlation and fluctuation. Energy scan and different collision systems.
Hydrodynamic QGP fluid + hadronic re-scattering; S.Soff, A.Bass, A.Dumitru, PRL 86 (2001) 3981