1 / 22

Measurement of phi and omega @RHIC-PHENIX

Measurement of phi and omega @RHIC-PHENIX. What is expected? Hadron suppression C.S.R. signal （ Flow → Talk by D.W.) （ Continuum → Talk by S.C.) What we have ?. outline. Misaki Ouchida ｆ or the PHENIX Collaboration Hiroshima University. 2010 WWND. What is expected. High pT physics.

arnaud
Download Presentation

Measurement of phi and omega @RHIC-PHENIX

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measurement of phi and omega @RHIC-PHENIX • What is expected? • Hadron suppression • C.S.R. signal （Flow → Talk by D.W.) （Continuum → Talk by S.C.) • What we have ? outline Misaki Ouchida ｆor the PHENIX Collaboration Hiroshima University 2010 WWND

  2. What is expected High pT physics Temperature QGP RHIC d u s Density The inclusive pi0 production in Au+Au Hadron Suppression Hadron Production will be suppressed due to the jet quenching occurred in the heavy-ion collisions as an effect of the matter How phi & omega behave? PRL 91. 072301 (2003)

  3. What is expected High pT physics Temperature QGP d u s Density Hadron Suppression Hadron Production will be suppressed due to the jet quenching occurred in the heavy-ion collisions as an effect of the matter How phi & omega behave? PRC 77. 064907 (2008)

  4. - <qq> quark condensate Temperature Density What is expected Low pT physics Hot/dense matter ↓ Quark condensate decrease ↓ changes hadron mass properties in medium Chiral Symmetry Restoration Measurements of vector mesons  Access quark condensate with theoretical calculations

  5. Prediction T.Hatsuda and S.Lee Phys.Rev.C46-1 1992 Model Prediction Unfortunately, quark condensates is not an observable  Link condesates and vector meson spectrum - Lowering of in-medium mass? - Broadening of resonance? R. Rapp, Phys. Rev. C63(2001) 054907

  6. How do we measure? φ mesons (tf=46fm/c) 　　φ→e+e- BR ~ 10-4 φ→K+K- BR ~ 50 % ω mesons (tw=23 fm/c) ω→e+e-BR ~ 10-5 ω→π0γ BR ~ 9 % 　　ω→π0π+π- BR ~ 90 % PHENIX spectrometer <Global detector> • BBC & ZDC : Event trigger, Collision vertex, Centrality <Central arm> • DC & PC : tracking, momentum • RICH & EMC : electron ID • TOF, EMC : hadron ID <Muon arm> • MuID : muon ID PHENIX acceptance pseud-rapidity range : |η| < 0.35 azimuthal angle : 2x90 degree

  7. •  e+e- (BR:7x10-3%) w p0g (BR:9%) Reconstructed Efficiency ωpT Can Approach to high pT Systematic Measurement • different decay mode (lepton, hadron) -different collision mode (p+p, d+Au, A+A) φ mesons 　　φ→e+e- BR ~ 10-4 φ→K+K- BR ~ 50 % ω mesons ω→e+e-BR ~ 10-5 ω→π0γ BR ~ 9 % 　　ω→π0π+π- BR ~ 90 % K+ e+  e- K- Advantage of Systematic Measurement -Leptonic Decay mode: no final distortion - Hadronic Decay mode: high BR, no ρ-contribution (e+e- case) - Wide kinematic coverage - Reference study (comparing collision system) - Line Shape Analysis (BR check)

  8. So far, what we have ? Collected Data (√s = 200 GeV) 　　- p+p (run5) - d+Au (run3, run8) - Cu+Cu (run5) - Au+Au (run4)

  9. Base Line – p+p p+p wφ e+e- φ K+K- No PID method was introduced to extend the acceptance to higher pT p+p w p+p-p0 φ K+K- Both leptonic and hadronic decay channel are measured

  10. Base Line – d+Au d+Au w p0g d+Au wφ e+e- φ K+K- Both leptonic and hadronic decay channel are measured

  11. Base Line • Spectra (p+p & d+Au) dAu pp Results are consistent Fitting of Levy func.

  12. Base Line • Spectra (p+p & d+Au) dAu pp Results are consistent Fitting of Levy func.

  13. R_dAu No suppression in d+Au

  14. In the case of A+A Yield analysis

  15. Trails – A+A BG BG Signal BG wφ Subtracting Backgrounds ( 2 body:wφ e+e- , φ K+K-) w,f→ee combinatorial backgrounds extract by Event Mixing f→K+K- w f

  16. Trails – A+A Subtracting Backgrounds ( 3 body:w p0g(p02g)) w Magenta: Uncorrelated BG + Correlated BG2 + Ks contribution Peripheral (cent 60~92 %) 3.5<pT<4.5[GeV/c] Reconstructed invariant mass BG2 Black: FG count BG1 after subtraction of BG1+BG2+BG3 BG3 w [GeV/c^2] Gaussian (Mean and With are Fixed by Embedding simulation)

  17. Results & Discussion • Spectra (Au+Au) φ K+K- , φ e+e-@ Au+Au PHENIX Preliminary 20 - 40% 0 - 20% MB 40 - 92% Suppression of phi in central collision No significant modification observed?

  18. Results & Discussion • Spectra (Au+Au) w p0g , w e+e-@ Au+Au PHENIX Preliminary Scaled from p+p spectra 0 - 20% MB 20 - 60% 60 - 92% Suppression of omega in central collision

  19. Results & Discussion • Baryon/meson difference is apparent • Suppression pattern of pi0 and eta is same • phi at intermediate pT do not follow pi0 and eta • omega in high pT needs more data • All suppression patterns are similar at high pT R_AA (CuCu and AuAu) The results are consistent Between CuCu and AuAu

  20.  e+ e - po   e+ e - signal electron partner positron needed for rejection Issues and Outlook • The discussion in low pT physics is hard due to low statistics and S/N • Run10 is now taking AuAu data • with activated HBD Dalitz rejector Hadron Blind Detector “combinatorial pairs” Able to reduce the BG from Dalitz and γconversion all signal

  21. Summary • PHENIX measured Low Mass Vector Meson, omega and phi production in both leptonic and hadronic channels in different collision system. • Spectra show good agreement in p+p and d+Au • Mass modification discussion is hard to discuss • Yield measurement provide intriguing systematic results of hadron suppression. Base line A+A

  22. Back up

More Related