20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba1 Rapporteur 3 Bulk Properties and Collective Phenomena ShinIchi Esumi Univ. of Tsukuba

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba2 dn/dy, spectra, chemical/thermal freeze-out stopping, radial flow, recombination HBT, global polarization rapidity dependence eccentricity definition event by event v 2 fluctuation v 1 and v 2 scaling jet and its correlation with v 2 charm quark interaction and collectivity direct photon as a probe of bulk matter

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba3 ‘ net ’ proton dN/dy AGS SPS RHIC 62 RHIC 200 LHC 5500 (BRAHMS preliminary) NA49 preliminary baryon transport (stopping)

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba4 STAR Preliminary hadron spectra after strong radial expansion STAR (  s NN =130 GeV) mass [GeV/c 2 ] Inverse slope parameter [GeV/c 2 ]

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba5 STAR Preliminary 5% central10% centralMin-Bias  Kp thermal fit BRAHMS hadron production at chemical freeze-out close to the phase boundary

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba6 p/   p/   baryon transport + radial flow + recombination + jet suppression Au+Au 200GeV STAR preliminary

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba7 m T (GeV/c) R inv (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, ChinaShinIchi Esumi, Univ. of Tsukuba8 global polarization Lambda polarization w.r.t. (normal to) directed event plane no significant signal observed, upper limit : |P ,  |~10 -2

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba9 y=0y=1y=3.1 pions kaons protons rapidity dependence of identified particle nuclear suppression No strong indication of rapidity dependence

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba10  =0  ≈3  K p rapidity dependence of identified particle v 2 BRAHMS preliminary No strong indication of rapidity dependence, the strong rapidity dependence on the integrated v 2 is more or less explained by the mean p T. Meson/baryon splitting might be different between y=0 and y=3, if statistical significance is improved.

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba11 Participant Eccentricity Standard Eccentricity 200 GeV arXiv:nucl-ex/ , submitted to PRL Cu+Cu Au+Au Cu+Cu Au+Au eccentricity definition

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba12 v 2 scales with and energy densidy

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba13 PHOBOS  part prediction MC with no fluctuations event by event v 2 fluctuation vs  part fluctuation This relative v2 fluctuation can be explained by initial  part fluctuation…

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba14 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.  STD  PART  MOD participant  modified participant    Cu+CuAu+Au impact parameter : b (fm)  x (fm) impact parameter : b (fm) y (fm) eccentricity re-visited Participant Modified Standard v2v2  =?

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba15  part 0-5% 1.5/0.9 = % 1.7/1.1 = 1.5 experiment Cu/Au v 2 ratio phobos 2.6/1.5 = /2.1 = 1.5 star v 2 {2}0-5% 3.7/2.5 = % 4.2/3.5 = 1.2 star v 2 {ftpc} /2.1 = /3.4 = 1.0 phenix 0-10% 4.0/3.0 = 1.3 STAR centrality dependence of v 2 comparison of v2 ratio : Cu+Cu/Au+Au (>1) at central (<10%) collisions between experiments PHENIX PRELIMINARY

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba16 STAR 200GeV Au+Au 20-60% PHENIX 200GeV Cu+Cu STAR 200GeV Cu+Cu 20-60% PHOBOS 200GeV Cu+Cu 20-40% PHOBOS 200GeV Au+Au 20-40% V 2 {2} V 2 {FTPC} V 2 {AA-pp} V 2 {2} V 2 {FTPC}  V 2 {4} PHENIX 200GeV Au+Au 30-40% V 2 {BBC R.P.} STAR FTPC and PHENIX BBC have about same acceptance.

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba17 v 1 scaling w.r.t. beam rapidity and v 1 wiggle (proton) Centrality scaling for v 1 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 spectator v1 direction anti-flow of p as seen in SPS Different trend could be caused by the different p T cut off. PHOBOS

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba18 v 2 scaling with m T -m + number of quark (same as hydro at low p T + number of quark) When the mass effect removed by m T -m, only the quark number ratio shows up! Is mass ordering of v 2 at low p T generated during or after hadronization? Feed-down for pion is visible in p T, but not in m T -m, because p T (daughter) < p T (parent), but m T -m(daughter) ~ m T -m(parent) … Decay kinematical effect is masked by the p T to m T -m transformation.

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba19 STAR preliminary v 2 scaling with m T -m + number of quark v2v2 p T (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 v 2 analysis, this is an indication that v 2 is already built up in early stage.

20 Nov 2006, Quark Matter, Shanghai, ChinaShinIchi Esumi, Univ. of Tsukuba20 STAR preliminary 0-12% 200 GeV Au+Au PHENIX nucl-ex/ PHENIX Preliminary 10-20% Au+Au 200GeV p T trig =2.5-4 GeV/c p T assoc =1-2.5 GeV/c STAR preliminary 0-12% Au+Au 200GeV p T trig =3-4 GeV/c p T assoc =1-2 GeV/c CERES preliminary 0-5% Pb +Au 17GeV p T trig =2.5-4 GeV/c p T assoc =1-2.5 GeV/c CERES preliminary 0-5% Pb +Au 17GeV p T trig =2.5-4 GeV/c p T 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, ChinaShinIchi Esumi, Univ. of Tsukuba21 STAR, PRL93 (2004) | trig - RP | PHENIX, nucl-ex/ jet modification and its correlation with v 2 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, ChinaShinIchi Esumi, Univ. of Tsukuba22 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, ChinaShinIchi Esumi, Univ. of Tsukuba23 N. Xu, SQM 2006, PHENIX ( , K, p, J/  ): PRC69, (04), QM05; STAR ( , ,  ): QM05 AuAu Central charm hadron AuAu Central , K, p AuAu Central strangeness hadron SQM06, Yifei Zhang RHIC 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, ChinaShinIchi Esumi, Univ. of Tsukuba24 PHENIX preliminary annihilation compton scattering Bremsstrahlung (energy loss) prompt photon v 2 = 0 v 2 < 0 thermal photon v 2 > 0 Jet-frag. photon from the survived parton v 2 > 0 Inclusive photon v 2 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, ChinaShinIchi Esumi, Univ. of Tsukuba25 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?