1. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. The 31 st International Symposium on Multiparticle Dynamics on 1-7, Sept. 2001 in Datong, China Correlation and fluctuation studies at RHIC Toru Sugitate Hiroshima University Sugitate@hepl.hiroshima-u.ac.jp

2. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. Multiparticle dynamics in high-energy heavy-ion collisions Relativistic Heavy Ion Collider (RHIC) begins smashing atoms at  s NN = 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. Temperature Baryon density Normal Nucleus Hadronic Matter Quark-Gluon Plasma quark confinement Chiral symmetry

3. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. In the Longitudinal Center of Mass System ( p 1 z + p 2 z = 0 ) ; It is obvious for a static source, but our source is expanding.. 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 TCTC QGP

4. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. The STAR (Solenoidal Tracker at RHIC) experiment at RHIC  K p d e STAR Acceptance 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 neutral particles.

5. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. The PHENIX (Pioneering High Energy Nuclear Interaction eXperiment) at RHIC Broadest possible study of A-A, p-A, p-p collisions to study 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.

6. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. 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 Side Q Out C 2 (Q; Q others < 80 MeV/c) First particle correlation data at RHIC. Consistent between two experiments. Positive pions show similar results. No surprise with the C 2 functions. 12-15% most central events in Au+Au at  s NN =130 GeV. Negative pions in the mid-rapidity. 3 dimensional analysis in the LCMS frame.

7. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ.  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.  s NN (GeV) 10 1100 R out /R side 0 1.5 0.5 1 4 2  (R out 2 -R side 2 ) E895 NA44 NA49 PHENIX E866 WA98 STAR  s NN (GeV) 101100 R out (fm) R side (fm) 8 4 6 8 4 6 8 4 6 2 1 0.4 0.8 1.2 0.6 R long (fm) No remarkable difference between R out and R side.   is similar to those at SPS/AGS. No indication of a long-lived mixed phase.

8. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. Centrality and m T dependences of the source size parameter STAR published data in PRL87 (2001)082301 1.0 0.4 0.8 1.2 0.6 +-+- 0.2 med high low centrality bin m T (GeV/c 2 ) 0.3 0.4 R out (fm) 8 4 6 R side (fm) 8 4 6 8 4 6 2 R long (fm)  + 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 m T. consistent with a hypothesis of hydrodynamical expanding sources. NA44 published in PRL 87(2001)112301 R=3.0 /  m T +-+- 0.2 med high low centrality bin m T (GeV/c 2 ) 0.3 0.4 R out (fm) 8 4 6 R side (fm) 8 4 6 8 4 6 2 R long (fm) Does the m T scaling observed at SPS explain the present R Trans and R Long data at RHIC ?

9. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. 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. The Net Baryon number in hadron gas The net Baryon number in a QGP with 2 massless flavor M. Asakawa presented in QM01; Then, we should see difference in; and

10. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. Event-by-event fluctuations in the mean P t in PHENIX Centrality: 0-5% PHENIX Preliminary (GeV/c) Data vs. Mixed Event (GeV/c), 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.

11. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. Event-by-event fluctuations in the mean E t in PHENIX Mean Max Simulation Centrality: 0-5% PHENIX Preliminary PbSc (GeV), Central Collisions by J. Mitchell (BNL) for the ACS on 8/30/01 Simulation for statistically independent emission incl. experimental biases.

12. ISMD31 / Sept. 4, 2001 Toru Sugitate / Hiroshima Univ. Summary and outlook of correlation and fluctuation studies at RHIC The source size parameters at  s NN = 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 and were seen by PHENIX, but some indication in charge independent 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 m T scaling at SPS explains the radii at RHIC?  Is there any universal scaling on  s?  Another hint; R Long ~ R Trans 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  s NN = 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