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Status of PHENIX Experiment

Status of PHENIX Experiment. K. Ozawa (University of Tokyo). University of Tokyo, Tsukuba University, Hiroshima University, KEK, Waseda University, Nagasaki Institute of Applied Science. Current status.

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Status of PHENIX Experiment

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  1. Status of PHENIX Experiment K. Ozawa (University of Tokyo) University of Tokyo, Tsukuba University, Hiroshima University, KEK, Waseda University, Nagasaki Institute of Applied Science

  2. Current status The project is associated with study of hot and dense nuclear matter generated by high energy heavy ion collisions. Relativistic Heavy Ion Collider (RHIC) and PHENIX detector system are constructed at Brookhaven National Laboratory (BNL). Japan-US collaboration works effectively in every steps of the experiment. Huge number of events are acquired in recent 10 years and many measurements suggest formation of Quark-Gluon-Plasma. US/J meeting

  3. Physics motivation Study of quark deconfinement Phase transition of “QCD vacuum” In ordinary matter, quarks are confined. QGP is a quark de-confined state. It can be reproduced and studied by RHIC. Observe Quark-Gluon-Plasma US/J meeting

  4. Experimental Method RHIC • High Energy Heavy Ion collisions at RHIC. • Au-Au • @ sNN = 200 GeV Measure matterproperties PHENIX Initial Energy Density / Temperature Thermalization and thermal parameters Quark Degree-of-Freedom of the matter Quark de-confinement Order parameter of the chiral symmetry Create high temperature matter. US/J meeting

  5. BBC RICH TOF Magnet coils RXPD AGEL PHENIX: Japanese Contribution Japanese Detectors in PHENIX • Construction • Done by 2004 • Operation • Costs • Man Power • Calibration • Electron Identification • Time of Flight • Trigger & Luminosity • Reaction Plane • Physics Analysis • ~ 3 Dr thesis per year US/J meeting

  6. History PHENIX Year Species s1/2 [GeV ] LdtNtot (sampled)Data Size Run3 2002/03 d-Au 200 2.74 nb-1 5.5 G 46 TB Run4 2003/04 Au-Au 200 241 mb-1 1.5 G 270 TB Run-7 2007 Au-Au 200 813 mb-1 5.1 G 650 TB Run-8 2008 d-Au 200 80 nb-1 160G 3.8 PB Run-10 2010 Au-Au 200 1300 mb-1 8.2 G 1.0 PB • Since June 2000, whole PHENIX detectors including Japanese detectors are well operated and huge statistics are obtained • With Run4and run7 integrated luminosity, several measurements are achieved. • v2 of identified particles, Jet energy loss, J/y suppression • Further physics results can be obtained with Run 10 data. US/J meeting

  7. Publication status • 88 papers published to date • 8 papers are submitted • citations extremely impressive • 4 250+ top cite paper • 20 100+ top cite paper • + 28 50+ top cite paper • PHENIX White paper (Nucl.Phys. A757,184, 2005) • 2nd most cited nucl-ex paper in 2007 • Total 829 citations • Most cited paper, with 503 citations is “Suppression of hadrons with large transverse momentum in central Au+Au collisions at s(NN)**(1/2) = 130-GeV” Adcox, et al., PRL 88, 022301 (2002) (Dr thesis, K. Oyama, University of Tokyo) US/J meeting

  8. Physics results US/J meeting

  9. A+A p+p High density Matter dNg/dy = 1000 （30～50 x Nucleus） • Measuring high pT particle yields: • Initial yields and pT distributions can be predicted from p+p measurements + pQCD + cold nuclear effects • Deviations can be attributed to the medium formed in A+A collisions US/J meeting

  10. p+p Jet tomography: Updated Angle correlation Collision Energy Dep. Big step between SPS and RHIC Angle correlation caused by Jet Correlation is disappeared in Au+Au Particle species Dep. ○proton ●Au+Au US/J meeting

  11. Thermalization Measurements of anisotropic particle emission Anisotropic flow of 7Li atom gas Large anisotropy Early Thermalize Particles are not interacted • Conserve initial isotropy Medium is formed & Thermalized • Geometry creates anisotropy US/J meeting

  12. Hydro + J/y T. Gunji et al. PRC 76:051901,2007 Deconfinement Quark number scaling J/y Melting Anisotropy is scaled by the number of constituent quark in meson and baryon Color Screening If Rforce ~ Rscreening < Rbind, qq is never bound. Only with de-confinement Measurement of Melting T KET: Kinetic Transverse Energy (ET – M0) Mass difference is corrected TJ/y = 2.0Tc f meson follows other mesons. Note: Mf ~ Mp US/J meeting

  13. Perfect Fluid Evidences for creation of Quark Gluon Plasma Enough Initial Energy and Temperature High gluon density matter is formed Thermalization is achieved Direct evidence of de-confinement Suggests QGP Measurements of h/s Press Releasein Japan Based on flow and charm measurements Relation with AdS/CFT Predicted limit US/J meeting

  14. Updates in the last year US/J meeting

  15. Electron pair measuremnts • De-confinement (J/ysuppression) • Charm, bottom quark in QGP • Chiral symmetry via f, w • Thermal photon via lepton pair p0 w f Correlated DD J/y PLB670, 310(2009) US/J meeting

  16. Final e+e- spectrum in Run4 arXiv:0706.3034 p+p NORMALIZED TO mee<100 MeV Clear enhancement is observed in the mass region below w. US/J meeting

  17. Model comparison arXiv:0706.3034 No model can reproduce experimental data at this moment. • Black Line • Baseline calculations • Colored lines • Several models • Low mass • M>0.4GeV/c2: • some calculations OK • M<0.4GeV/c2: not reproduced • Mass modification • Thermal Radiation Both statistical and systematic errors depend on huge background caused by Dalitz decays and g conversions US/J meeting

  18. signal electron e- partner positron needed for rejection Cherenkov blobs e+ qpair opening angle ~ 1 m Dalitz Rejecter around vertex • Window less Cerenkov conter • One gas volume • Same gas for Radiator and detection • CF4 (γｔｈ~28) • CsI photo casode • UV sensitive (6 eV, 200nm) US/J meeting

  19. Performance in Run9 Rejection factor Hadron Projected Performance @ Run10 few pe Np.e. of single electron Single electron Signal significance 1.4 /nb recorded improves effective statistics by ≥ 35 ~20 pe Luminosity [unit of Run4 ] US/J meeting

  20. Thermal photon Direct Photon arXiv:0804.4168 • p+p (Run5) result with * method agrees with NLO pQCD predictions, and with statistical method at high pT • Confirmation of the method • For Au+Au (Run4), there is a significant low pT excess above p+p expectations • Interpreted as thermal emission -> Initial T To be published in PRL US/J meeting

  21. Hottest experiment! We have a press release at APS spring meeting. Our experiment is introduced as a hottest science experiment on the planet! US/J meeting

  22. Future Prospects We need to explore QCD nature QCD Phase Transition In QCD phase diagram, critical point is important, since the point can determine the absolute scale. RHIC can explore the region below using collision energy scan. Need Luminosity US/J meeting

  23. Summary The project is associated with study of hot and dense nuclear matter to observe Quark-Gluon-Plasma and investigate its properties. For this purpose, Relativistic Heavy Ion Collider (RHIC) and PHENIX detector system are constructed at Brookhaven National Laboratory (BNL). Huge number of events are acquired in recent 10 years and many measurements suggest generation of Quark-Gluon-Plasma. US/J meeting

  24. Back ups US/J meeting

  25. Chiral symmetry in hadronic matter R. Rapp (Nucl. Phys A661(1999) 238c Au+Au Background Rejection with new detector  e+ e - po   e+ e - Installed in 2009 Fully operated in 2010 run Also, long data acquisition is expected in 2010 • As a signal of chiral symmetry restoration • Measure vector mesons. • Mass shift or modification is expected. • Lepton decays become good probes. • Not interacting “strongly.” • Current results has poor statistics due to large background US/J meeting

  26. Thermal photon Direct photon Directly emitted from the medium Not from hadron Hard photon Initial pQCD Thermal photon Hadron gas QGP Turbide, Rapp, Gale, Phys. Rev. C 69 (014903), 2004 • After subtraction of large background from hadron decays, • Window for thermal photons from QGP in this calculation: pT = 1 - 3 GeV/c • pQCD calculation should be confirmed in High pT region US/J meeting

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