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

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

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

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

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

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

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

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

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

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

eccentricity definition Standard Eccentricity Participant Eccentricity 200 GeV 200 GeV Cu+Cu Cu+Cu Au+Au Au+Au arXiv:nucl-ex/0610037, submitted to PRL 20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba

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

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

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

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% 1.5/0.9 = 1.7 5-10% 1.7/1.1 = 1.5 experiment Cu/Au v2 ratio phobos 2.6/1.5 = 1.7 3.1/2.1 = 1.5 star v2{2}0-5% 3.7/2.5 = 1.5 5-10% 4.2/3.5 = 1.2 star v2{ftpc} 0-5 3.0/2.1 = 1.4 5-10 3.4/3.4 = 1.0 phenix 0-10% 4.0/3.0 = 1.3 20 Nov 2006, Quark Matter, Shanghai, China ShinIchi Esumi, Univ. of Tsukuba

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

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

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

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

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/0611019 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

jet modification and its correlation with v2 STAR, PRL93 (2004) 252301. PHENIX, nucl-ex/0510019. |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

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

more hints of charm quark collectivity N. Xu, SQM 2006, PHENIX (, K, p, J/): PRC69, 034909(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

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

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