1 / 43

Long range rapidity correlations in high energy nucleus collisions at RHIC and LHC

Long range rapidity correlations in high energy nucleus collisions at RHIC and LHC. Heavy Ion Pub @ Ohsaka University Takahito Todoroki University of Tsukuba & Riken Nishina Center. Outline. Overview of basic ridge property Ridge study via Df correlations with respect to Reaction Plane

genero
Download Presentation

Long range rapidity correlations in high energy nucleus collisions at RHIC and LHC

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. Long range rapidity correlations in high energy nucleus collisions at RHIC and LHC Heavy Ion Pub @ Ohsaka University Takahito Todoroki University of Tsukuba & Riken Nishina Center T. Todoroki, University of Tsukuba

  2. Outline • Overview of basic ridge property • Ridge study via Df correlations with respect to Reaction Plane • Triangular flow • Dh correlations with respect to trigger h • Ridge in high multiplicity p+p events at LHC-CMS • Summary T. Todoroki, University of Tsukuba

  3. Long range rapidity correlations • Long range rapidity correlations up to large rapidity = “Ridge” • Seen in Au+Au, absent in d+Au collisions • Superposition of jet and ridge at Df~0 & Dh~0 in Au+Au collisions Phys. Rev. C 80, 064912 (2009) 2< pTasso < pTtrig 2< pTasso < pTtrig Jet Jet Ridge T. Todoroki, University of Tsukuba

  4. pT spectra of Jet and Ridge yield Phys. Rev. C 80, 064912 (2009) • Jet spectrum is increasing with pTtrig as jet fragmentation • Ridge spectrum is softer and approximately independent of pTtrig • Ridge is “bulk-like” T. Todoroki, University of Tsukuba

  5. Ridge shape gets clearer with pT T. Todoroki, University of Tsukuba

  6. Centrality evolution of Ridge Au+Au 200GeV data - fit (except same-side peak) • Rapid transition from 55-65% to 46-55% • Small change to most central after transition • Ridge may be phenomena of underlying event pT > 0.15 GeV M.Daughersity, QM08, J.Phys.G35:104090,2008 83-94% 55-65% 46-55% 0-5% STAR Preliminary STAR Preliminary STAR Preliminary STAR Preliminary ηΔ width T. Todoroki, University of Tsukuba

  7. Ridge and Jet Df correlations with respect to Reaction Plane • Jet = (|Dh|<0.7) -Accep*(|Dh|>0.7) • |Dh|>0.7 = near-side ridge + away-side • Flow subtraction by ZYAM T. Todoroki, University of Tsukuba

  8. Ridge correlations have reaction plane dependence 1 2 3 4 5 6 T. Todoroki, University of Tsukuba

  9. Correlated Emission Model Chiu,Hwa, arXiv:0809.3018 Correlated Emission Model (CEM) out-of-plane jet flow misaligned less ridge in-plane jet flow aligned more ridge Asymmetric ridge peak predicted T. Todoroki, University of Tsukuba

  10. Ridge and Jet Df correlations with respect to Reaction Plane • Jet = (|Dh|<0.7) -Accep*(|Dh|>0.7) • |Dh|>0.7 = near-side ridge + away-side • Flow subtraction by ZYAM • 2 Gaussian fit to away side and subtracted • Ridge obtained 5 6 3 4 1 2 Df T. Todoroki, University of Tsukuba

  11. Near side peak asymmetry • Jet shape is symmetric • Ridge is asymmetric! • shift to Df>0 side • Ridge may come from jet-flow alignment 4 5 3 2 6 1 T. Todoroki, University of Tsukuba

  12. Back to Back Ridge • Jet = (|Dh|<0.7) -Accep*(|Dh|>0.7) • |Dh|>0.7 = near-side ridge + away-side • Flow subtraction by ZYAM • Fit : Back-to-Back Ridge + away conical emissions T. Todoroki, University of Tsukuba

  13. Triangular Flow Pictures : Alver RHIC-AGS Meeting 2010 • Triangular flow is possible source of ridge! arXiv:0806.0513v1 T. Todoroki, University of Tsukuba

  14. Comparison of AMPT and STAR • v2 & v3 are depending on initial geometry in AMPT • AMPT simulations have good consistency with data at pT >0.8GeV VnD = <cos n(fasso - ftrig)>~ Vn2 arXiv:1003.0194v3 T. Todoroki, University of Tsukuba

  15. S. Esumi WWND2011 T. Todoroki, University of Tsukuba

  16. Dh correlations with respect to trigger h • Jet and Ridge property as function of trigger h • Back/Forward asymmetry of correlation shapes • Gradient of correlation functions T. Todoroki, University of Tsukuba

  17. PYTHIA8 T. Todoroki, University of Tsukuba

  18. AMPT Flow Not Subtracted Near side : |Df| < p/4 0 ~ 20% C2 : arbitrary unit 20 ~ 50% 50 ~ 93% Dh = hasso- htrig:[-4,+4] htrig= -2.0 htrig= 2.0 htrig= 0 T. Todoroki, University of Tsukuba

  19. PHENIX Data Analysis • Trigger “sign” selection : “h<0” and “h>0” • Precise trigger selection : [-0.35,0.35] 14bins. 0.05 step. • Dh correlations : projected from Df - Dh correlations • Near side : |Df| < p/4 • Away side : |Df - p| < p/4 • Superposition of jet and ridge due to central arm accep. |h|<0.35 T. Todoroki, University of Tsukuba

  20. Trigger h sign selected correlations h>0 h<0 T. Todoroki, University of Tsukuba

  21. Projected Dh correlations : Trigger h sign selected Near : |Df|<p/4 Away: |Df - p|<p/4 T. Todoroki, University of Tsukuba

  22. Near side Dh correlations : precise trigger selection Near : |Df|<p/4 T. Todoroki, University of Tsukuba

  23. Away side Dh correlations : precise trigger selection Away: |Df - p|<p/4 T. Todoroki, University of Tsukuba

  24. Backward / Forward asymmetry • Yield Ratio = (AvgForward - AvgBackward)/(AvgForward + AvgBackward) • Forward : 0 < Dh <0.25 • Backward : -0.25 < Dh <0 • YR=0 : symmetric shape • YR>0 or <0 : shift for Forward or Backward direction “Forward” : Dh>0 “Backward” : Dh<0 Centrality : 0~20 trigger (hadron): Pt 2~4GeV ηtrig [0, 0.05] associate (hadron) : Pt 1~2GeV Backward Forward T. Todoroki, University of Tsukuba

  25. Backward / Forward asymmetry : trigger sign selection • Degree of asymmetry • at most 2s in peripheral at near side • at most 1s in peripheral at away side T. Todoroki, University of Tsukuba

  26. Backward / Forward asymmetry : trigger precise selection • Large statistical & systematic error on both near and away side T. Todoroki, University of Tsukuba

  27. Gradient of correlations as function of trig h • Fitting function : [0] + [1]*x • Fitting range • Dh : [ 0,0.35] if htrig <0 • Dh : [-0.35,0] if htrig <0 Centrality : 0~20 trigger (hadron): Pt 2~4GeV ηtrig [0, 0.05] associate (hadron) : Pt 1~2GeV if htrig >0 if htrig <0 T. Todoroki, University of Tsukuba

  28. Gradient of correlations seems to be flat • Gradient of correlations seems to be flat at near side • Away side also seems to be flat though still large statistical error T. Todoroki, University of Tsukuba

  29. Correlations in high multiplicity p+p events at LHC-CMS Minimum Bias no cut on multiplicity High multiplicity data set and N > 110 The peak is truncated in both distributions Back-to-back jet correlations enhanced in high multiplicity sample. T. Todoroki, University of Tsukuba

  30. Minimum Bias no cut on multiplicity High multiplicity data set and N>110 New “ridge-like” structure extending to large  at  ~ 0 T. Todoroki, University of Tsukuba

  31. Data and PYTHIA8 T. Todoroki, University of Tsukuba

  32. Other simulation models T. Todoroki, University of Tsukuba

  33. Data and PYTHIAD6T at 0.9, 2.36 and 7 TeV PYTHIA D6T PT inclusive T. Todoroki, University of Tsukuba

  34. Comparison 7 TeV p+p and 200 GeV Cu+Cu correlations • Correlations in Cu+Cu at similar multiplicity dominated by flow. • How correlation shape changed if v2 exists in high mult. p+p event? • Need to survey azimuthal dynamics in high mult. p+p events High multiplicity data set N>110 Hard Probe 2010, Putschke T. Todoroki, University of Tsukuba

  35. Accumulative azimuthal correlations • Consistent with p+p minimum bias at peripheral • Enhance of Au+Au correlations at mid central & central by flow-like component • Method to search the possible modification in high multiplicity p+p events from minimum bias because no event plane needed STAR AuAu 200GeV arxiv:nucl-ex/0407007v3 <Si cos2(ftrig - fiasso)> = Mult.*v2 (pTtrig) v2asso+{non-flow} 0.15 < pTasso <2.0GeV/c at |h|<1.0 Trigger T. Todoroki, University of Tsukuba

  36. Accumulative correlations in high multiplicity p+p events at 200 GeV Midori Kajigaya Univ. of Tsukuba • Enhance in mid-rapidity high multiplicity event • Azimuthal dynamics in p+p events depends on multiplicity if track number count and calculation done in same rapidity range. <Si cos2(fPt - fi)> = Mult.*v2 (pT) v2asso + {non-flow} T. Todoroki, University of Tsukuba

  37. Possible ridge in p+p collisions at RHIC energy? • data to analyze : 500GeV, 200GeV and 62.4 GeV CERN-ISR Nucl. Phys. B145 (1978) 305-348 p+p √s = 52.6 GeV 0.5< Passo T. Todoroki, University of Tsukuba

  38. Summary • Overview of basic ridge property • Ridge study via Df correlations with respect to Reaction Plane • Ridge depends on Reaction Plane • Triangular flow • Possible source of ridge • AMPT well describes STAR experimental data at pT >0.8GeV • Dh correlations with respect to trigger h • No trigger h dependence seen in PHENIX acceptance… • Ridge in high multiplicity p+p events at LHC-CMS T. Todoroki, University of Tsukuba

  39. Back Up Slides T. Todoroki, University of Tsukuba

  40. T. Todoroki, University of Tsukuba

  41. T. Todoroki, University of Tsukuba

  42. None trigger selected Df-Dh correlations T. Todoroki, University of Tsukuba

  43. T. Todoroki, University of Tsukuba

More Related