Event anisotropy of identified p0, g and e compared to charged p, K, p, and din sNN = 200 GeV Au+Au at PHENIXMasashi Kanetafor the PHENIX collaboration

USAAbilene Christian University, Abilene, TXBrookhaven National Laboratory, Upton, NYUniversity of California - Riverside, Riverside, CAUniversity of Colorado, Boulder, COColumbia University, Nevis Laboratories, Irvington, NYFlorida State University, Tallahassee, FLFlorida Technical University, Melbourne, FLGeorgia State University, Atlanta, GAUniversity of Illinois Urbana Champaign, Urbana-Champaign, ILIowa State University and Ames Laboratory, Ames, IALos Alamos National Laboratory, Los Alamos, NMLawrence Livermore National Laboratory, Livermore, CaUniversity of New Mexico, Albuquerque, NMNew Mexico State University, Las Cruces, NMDept. of Chemistry, Stony Brook Univ., Stony Brook, NYDept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY Oak Ridge National Laboratory, Oak Ridge, TNUniversity of Tennessee, Knoxville, TNVanderbilt University, Nashville, TNBrazilUniversity of So Paulo, So PauloChinaAcademia Sinica, Taipei, TaiwanChina Institute of Atomic Energy, BeijingPeking University, BeijingFranceLPC, University de Clermont-Ferrand, Clermont-FerrandDapnia, CEA Saclay, Gif-sur-YvetteIPN-Orsay, Universite Paris Sud, CNRS-IN2P3, OrsayLLR, Ecle Polytechnique, CNRS-IN2P3, PalaiseauSUBATECH, Ecle des Mines at Nantes, NantesGermanyUniversity of Mnster, MnsterHungaryCentral Research Institute for Physics (KFKI), BudapestDebrecen University, DebrecenEtvs Lornd University (ELTE), Budapest IndiaBanaras Hindu University, BanarasBhabha Atomic Research Centre, BombayIsraelWeizmann Institute, RehovotJapanCenter for Nuclear Study, University of Tokyo, TokyoHiroshima University, Higashi-HiroshimaKEK, Institute for High Energy Physics, TsukubaKyoto University, KyotoNagasaki Institute of Applied Science, NagasakiRIKEN, Institute for Physical and Chemical Research, WakoRIKEN-BNL Research Center, Upton, NYRikkyo University, TokyoTokyo Institute of Technology, TokyoUniversity of Tsukuba, TsukubaWaseda University, Tokyo S. KoreaCyclotron Application Laboratory, KAERI, SeoulKangnung National University, KangnungKorea University, SeoulMyong Ji University, Yongin CitySystem Electronics Laboratory, Seoul Nat. University, SeoulYonsei University, SeoulRussiaInstitute of High Energy Physics, ProtovinoJoint Institute for Nuclear Research, DubnaKurchatov Institute, MoscowPNPI, St. Petersburg Nuclear Physics Institute, St. PetersburgSt. Petersburg State Technical University, St. PetersburgSwedenLund University, Lund 12 Countries; 58 Institutions; 480 Participants**as of January 2004

AnnouncementThe flow and event anisotropy from the PHENIX collaborators in the poster session* StudentsShingo Sakai*Azimuthal anisotropy of electrons/positrons in 200 GeV Au+Au collisions at RHIC-PHENIXAndrey Kazantsev*Elliptic flow of inclusive photons in Au+Au collisions at sNN=200 GeV from the PHENIX experiment at RHICHiroshi Masui*Measurement of directed flow in sNN=200 GeV Au+Au, d+Au, p+p collisions at RHIC-PHENIXAkio KiyomichiRadial flow study from identified hadron spectra in Au+Au collisions at sNN=200 GeV (at PHENIX)Michael Issah*Azimuthal anisotropy measurements in PHENIX via cummulants of Multiparticle azimuthal correlationsDebsankar MukhopadhyayElliptic flow of f mesons in Au+Au collisions at sNN=200 GeV (at PHENIX)ShinIchi EsumiAnalysis of event anisotropy and azimuthal pair correlation

MotivationsEvent anisotropySensitive to the initial stateCollectivity of hadron/parton thermalization / recombinationEnergy loss by Jet quenching dense matter

p0Large pT coverage as an identified hadronLarge contribution of the decay to the following inclusive measurementsPhotonRadiation / Compton from hot gasPhoton flow?Electron/positronOpen charm and bottomFlow and energy loss of heavy flavors?

The PHENIX experiment at RHICPhotons/p0Tracking : vertex be BBC to EMC hit positionsPID : EMCalEvent centralityBBC and ZDCElectronsTrackingDC, PC hits, vertex by BBCPIDRICH (pT

Method of v2 MeasurementDefine reaction plane by charged multiplicity on Beam-Beam CountersPhotonsObtained the second harmonic coefficient v2 from p0p0 reconstruction and background subtract (combinatorial and the others)For each pT, azimuthal angle, centralityCombine both informationCounting number of p0 as a function of f-r and fit by the formula ElectronsBoth methods are usedevent anisotropy parameter measuredazimuthal angle of the particlereaction plane anglevnreal = vnmeasured/ (reaction plane resolution)n Note: the detail of reaction plane definition will be found in nucl-ex/0305013

Reaction plane definition

g & p0 v2

Inclusive photon v2 and p0 v2 in 200 GeV Au+AuInclusive photon v2 shows similar tendency with p0Need more statistics to see photon v2 after p0 (and also h) decay effect subtractionvertical bar : stat. errorcurves, gray box : sys. errorphenix preliminaryNote : Inclusive photon = including all of the decay effect from hadrons phenix preliminaryphenix preliminarypT [GeV/c], 200 GeV Au+Au, 200 GeV Au+Au, 200 GeV Au+Au

p0 decay effect for photon v2 (MC)Tool is ready for the decay effect in photons0 1 2 3 4 50.35

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-0.05v20 1 2 3 4 5pT [GeV/c]p0 v2 for MC inputp0 v2 generatedg v2 from p0 decayTest 1Test 2

vs. centrality from 200 GeV Au+AuVertical bar : stat. errorGray Box : sys. errorNpart26 46 74 114 167 235 325Npart26 46 74 114 167 235 325phenix preliminaryphenix preliminary200 GeV Au+Au200 GeV Au+Au

v2 vs. pT vs. centrality from 200 GeV Au+AuThe charged p and K v2 are shown only with statistical errorsStatistical error is shown by error barSystematic error from p0 count method and reaction plane determination is shown by horizontal barThe data point stays at in the bin and horizontal bar shows the bin rangeCharged meson v2 consistent with p0 v2 in pT

v2 vs. pT (Min. Bias) from 200 GeV Au+AuIdentified particle v2 up to pT=10 GeV/c}nucl-ex/0305013phenix preliminary200 GeV Au+Au Min. Bias36.3106 [events] = 5.3 [(mb)-1]AlsoSimilar pT dependence with charged hadron v2Low pT : consistent with hydrodynamical calculationHigh pT : interesting to compare to a jet quenching calculation/ fragmentation-recombination model0.50.4Consistent with charged pionsVertical bar : stat. errorcurves, Gray Box : sys. error

The data point :at in the bin

v2 : Identified hadrons at mid-rapidityPHENIX p, K, pin nucl-ex/0305013and they are consistent with STAR data

PHENIX p0, d+dpreliminary data

STAR K0S , L+Lin nucl-ex/0306007200 GeV Au+Au Min. Bias

Coalescence pictureIt is established for the nuclei cross section

A : nuclear numberP : momentump = P/ABA : coalescence parameter

Quark coalescence?Phys. Rev. Lett. 91 (2003) 092301, D. Molnar and S.A. Voloshinqqmeson, qqq(qqq)Baryon

What data looks like?

----Non-strange and strange mesons and baryons seem to be merged around pT/nquark 1-3 GeV/cWith more statistics, we may discuss precisely

e v2

Non-photonic e v2Non-photonic electron (sorry for jargon) meansMeasured electron minus background:hadron decayg conversionthat is, charmed (+bottomed) electronwe thinkTwo scenarios in nucl-th/0312100thermalized charm + transverse flowno re-interactionData is consistent with both scenariosHave a look of the poster for detail discussionShingo SakaiAzimuthal Anisotropy of electrons/positrons in 200 GeV Au+Au Collisions at RHIC-PHENIXTakashi HachiyaSingle Electrons From Semi-leptonic Decays of Heavy Flavor in Au+Au Collisions at sNN=200 GeV

Summary

SummaryFirst measurement of p0, g, e v2 at RHICp0 v2Minimum bias data (pT =1-10 GeV/c)v2 at the highest pT from the identified particle analysisNon-zero p0 v2 up to pT ~8 GeV/cCharged p v2 consistent with p0 v2 in pT =1-3 GeV/cQuark coalescence picture seems to work from combining various hadron v2s at RHICg v2Centrality (top 20, 20-40, 40-60%) and pT dependence (in pT

New results of charged hadron vnEllipticFlowDirectedFlowHave a look of the poster for detail discussionHiroshi MasuiMeasurement of directed flow in sNN=200 GeV Au+Au, d+Au, p+p collisions at RHIC-PHENIX

Backup

Example plots from the p0 v2 analysis proceduresall histograms are checked by eyes!!

Tooooooooooooo many histograms checked

v2 vs. pT (Minimum Bias) from 200GeV Au+Auphenix preliminarynucl-ex/030501336.3106 [events] = 5.3+0.5-0.4 [(mb)-1]

Comparison with a modelHydrodynamical calculation agreed in pT~

Comparison with a modelComparison with a model which is described in nucl-th/0306027. Here we don't want to discuss which model can describe the data. To conclude which model can describe the data, we need much more statistics in high pT region.Special thanks toC. Nonaka (one of authors)of nucl-th/0306027 fordata of model calculation phenix preliminary

Photon purity with cuts

Systematic errorsdifferent methods for extracting v2different reaction planes methodsdifferent colors for the sys. errors.

Particle identificationsRequirement for photonDead and noisy EMC towers are removed for the analysisPID cuts: c2

Charmed electron v2

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Let me start event anisotropy talk from PHENIX about pi zero gamma and electron in 200 GeV Gold on Gold collisions.

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This is the PHENIX collaboration from 12 countries, 58 institutions and 480 participants.20 sec

Before start of my talk, I want to mention PHENIX poster related flow and event anisotropy.The names colored by red are students.It is not too late to go to poster session to read it.Please go the poster session and talk with those students, especially.90 sec

We are interested in event anisotropy. It is one of reasons why you are here. OK?

The event anisotropy is sensitive to the initial state.In the low pT region, we see collectivity of hadron and parton, and it relate to thermalization and recombination in the early stage.And the energy loss by jet quenching is also important to find an evidence of dense matter, that is, QGP.

This talk focuses on pi0, photon, and electrons.pi0 is good observable as identified hadron because technically the pT coverage in larger than the other hadrons.And it makes large contribution of the decay to the photon and electrons yields.

We can have early stage of information by photon due to small cross section.We dont know whether photon flow exist, but if there is, it is interesting.

Our goal of electron analysis is for the open charm and bottom measurement.It is interesting to see flow and energy loss of heavy flavors.60 sec

The phenix experiment is at RHIC where stay in New York, Long Islands.You can see the RHIC from the satellite.The PHENIX is here at RHIC.Photons pi0 are measured be Electro-Magnetic Calorimeters.Electron is identified by RICH detector and EMC. The event centrality is defined by Beam-Beam counters and Zero-Degree Calorimeter stay hereThe selection of centrality is like this in PHENIX.

The analysis of pi zero v2 is done as the following steps.The Reaction plane is defined by charged multiplicity on Beam-Beam counters.The pi zero is reconstructed by two photon measured by EMC.Both information are combined and we obtained pi zero distribution as a function of the following formula.Here, the cross section is describe pT, rapidity and Fourier expansion of phi minus reaction plane.The vn is event anisotropy parameter measured and it is smeared by uncertainty of reaction plane.It is corrected by reaction plane resolution.

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let me start from gamma and pi0 v2 results.90 sec

Here is inclusive photon v2 and pi0 v2 as a function of pT for there centrality bins, top 20, 20-40, 40-60 %.You can see the both v2 are increasing with pT until around 3 GeV of pT, then saturated.The photon we measured is including hadron decays mainly pi0.For the our goal, we need to subtract the decay effect to see thermal and direct photonHowever, to see them, we need more statistics.

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I said, we need more statistics.However, it is no reason to wait for starting the decay effect study until we have fine data.This is a result of the study.Assuming pi0 v2 as shown by solid line, we can generate pi0 and process decay effect in Monte-Carlo.The tool is ready, then once we have better statistics we can subtract the decay effect from inclusive photon.

This slide shows analysis procedure.At first, invariant mass distributions of gamma pair are obtained from same event and mixed event.The black points are from same event and red is from mixed event.To generate mixed event. we select similar reaction plane direction, centrality and vertex positions.After combinatorial background subtraction, the distribution is like this.You can see the other component of background around pi zero peak.Its origin are hadronic shower, conversion electron, and also a correlation of gamma-gamma in the event.However, our goal is to count number of pi zero, therefore we assumed the second background by linearshape to subtract second background.After counting number of pi zero, it is plotted as a function of phi minus reaction plane.To obtained v2, we used this formula.The red curve shows fit results and green lines shows deviation bye error of v2. Counting number of pi zero is done for each centrality, pT, and phi minus reaction plane.To check the analysis confidence, I checked all of mass distribution bin by bin.Here I show the examplesinvariant distribution before and after combinatorial background.then pi 0 as a function of phi minus reaction plane