1. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi1 Jet correlation (Mach-cone, Ridge) at RHIC ShinIchi Esumi Inst. of Physics, Univ. of Tsukuba Contents Jet-Suppression and Modification Mach-cone and Ridge Identified Particle Correlation Correlation w.r.t. Reaction Plane

2. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi2  Au + Au Use Jet as a probe of High-Energy and Density Matter Jet in p+p, d+Au or Peripheral Au+Au Collision as a Base Line Subtraction of Non-Correlated BG in Central Heavy-Ion Collisions p + p Au + Aud + Au

3. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi3 RHIC 200GeVSPS 17GeVRHIC 62GeV PHENIX nucl-ex/0611019 S.Kniege, ISMD 2007 jet pp Au Jet suppression modification with 2-particle  correlation

4. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi4 p+p vs Au+Au cent 60-92%

5. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi5 p+p vs Au+Au cent 0-20%

6. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi6 STAR, Phys. Rev. Lett. 97 (2006) 162301 8 < pT(trig) < 15 GeV/c

7. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi7 Away Region Shoulder Region Head Region Shoulder Region Near Region large BG subtraction with v 2 like flow shape  region double peak region Same SideFar Side description of jet shape with several key words

8. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi8 Phys. Rev. Lett. 97, 052301 (2006) Leading hadrons Medium PRL 98 232302 (2007)

9. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi9 System Size and Beam Energy Dependence of Jet Shape nucl-ex/0611019 No energy dependence (62 ~ 200GeV) Rapid change between N part = 0 ~ 100 Almost no change above N part > 100

10. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi10 arXiv:0801.4545 Transverse Momentum (Trigger, Associate) Dependence of Jet Shape Suppression in both near/away side peak at high p T Enhancement in near side peak at low p T Development of away side shoulder at low p T No p T dependence of shoulder peak position

11. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi11 STAR Preliminary (  1 -  2 )/2 STAR Preliminary Cone angle (radians) p T (GeV/c) d+Au Collisions Au+Au Central 0-12% 3-particle correlation “  12 vs  13 ” No p T dependence, too. Trigger Asso.1 Asso.2

12. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi12 along azimuth Polar plot 3 Particle Correlations in High pT Framework (*) Normal Jet Same Side Away Side Assoc. pTs (2,3) *  12 *  = along radius *  12 *  13 *  _ = Hi pT(1)

13. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi13 Deflected jet sim 3-Particle di-jet correlations allow a distinction between different mechanistic scenarios ! Mach Cone sim Deflected and Cone Jet Sims 2-particle Correlations matched High pT(1)

14. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi14  *=   *=  PHENIX Preliminary Cone like Jets Deflected Jets Deflected jet simulation Mach Cone simulation

15. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi15 p+p, peripheral Au+Au central Au+Au PHENIX QM08 d+Au, 200 GeV STAR QM06  (rad)  Ridge “jet” Au+Au, 200 GeV

16. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi16 preliminary Jet+Ridge (  ) Jet (  ) Jet  ) yield ,  ) N part Au+Au 0-10% Ridge “jet ” STAR QM06

17. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi17 QM08 PHENIX Centrality Dependence of Ridge and Shoulder Yield and Both ridge and shoulder yields increase linearly with N part. Similar (flat) centrality dependence on inverse slope parameter for both ridge and shoulder. Jet (p+p) like p T shape is harder than ridge, ridge is harder than shoulder, shoulder is similar to inclusive.

18. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi18 STAR Preliminary T Inclusive ~ T Shoulder ~ T Ridge < T Jet QM06 QM08 ridge jet inclusive << Both ridge and shoulder are almost independent with centrality and trigger p T selections. It’s just like a bulk matter… suspicious on BG(bulk) subtraction… but this is what we see…

19. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi19 y t1 y t2 transverse correlations y t ~ ln(p t ) 0.5 1 2 3 4 p T (Gev/c) STAR Preliminary 2-particle correlation without high p T trigger selection 200GeV p+p hard component ηΔηΔ φΔφΔ soft component ηΔηΔ φΔφΔ Longitudinal Fragmentation (“strings”) 1D Gaussian, US pairs HBT peak at origin, LS pairs Minijets 2D Gaussian at origin, away-side peak actually cos(φ Δ ) J of Phys: Conf 27 (2005) 98 These structures define minijet correlations M. Daugherity, QM08 axial correlations ηΔηΔ φΔφΔ

20. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi20 longitudinal fragmentation 1D gaussian HBT, res., e+e- 2D exponential Minijet Peak 2D gaussian Away-side -cos(φ) Δη Δφ Elliptic flow cos(2φ Δ ) 1.2M minbias 200 GeV Au+Au events Included all tracks with p T > 0.15 GeV/c, |  | < 1, full  84-93% 28-38% 75-84% 19-28% 65-75%55-65%46-55% 9-19%5-9%0-5% M. Daugherity, QM08 STAR Preliminary

21. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi21 Centrality 200 GeV 62 GeV STAR Preliminary Peak AmplitudePeak η WidthPeak φ Width HIJING 1.382 default 200 GeV, quench off binary scaling assumption in Kharzeev and Nardi model data - fit (except same-side peak) Shape changes little from peripheral to the transition 83-94%55-65% η Δ width STAR Preliminary Large change within ~10% centrality 46-55% STAR Preliminary Smaller change from transition to most central 0-5% STAR Preliminary QM08 STAR Extracted 2-D near-side Gaussian parameters are shown. The strong  width change vs centrality should have a relation to the ridge formation. longitudinal (  density correlation length

22. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi22 arXiv:0712.3033 Near/Away-side B/M ratio increases in central Away-side B/M ratios approach inclusive values Incompatible with in-vacuum fragmentation Hadron trigger with identified associate Baryon/Meson

23. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi23 Baryon/meson ratio in ridge close to inclusive, in jet close to p+p p T trig > 4.0 GeV/c 2.0 < p T Assoc < p T trig C. Suarez et al, QM08 M. Lamont et al, QM05 J. Bielcikova et al, WWND07, C. Nattrass et al, QM08 Different production mechanisms for ridge and jet? Au+Au: 2 < p T trig < 3 GeV/c Cu+Cu: 3 < p T trig < 6 GeV/c p+p /  + +  - Associated baryon/meson ratios

24. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi24 Idea: Distinguish and No acceptance 1 jet-like associated, 1 ridge-like: Bands along axes Both ridge particles on one side: diagonal structure Ridge particles on either side: uniform  -   1  2 trigger No acceptance Ridge event-by-event: 3-particle 

25. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi25 STAR Preliminary dAu AuAu 0-12% STAR Preliminary dAu AuAu 0-12% 3<p T Trig <10 GeV/c 1<p T Asso <3 GeV/c Shaded : sys. error. Line : v2 uncer. STAR Preliminary dAu AuAu 0-12% P. Netrakanti et al, QM08 Note : 2x1 b.g. subtracted Radial distribution  -  structure: central peak + uniform No substructure in ridge: no gluon fragments? Note absence of excess along axes: no jet+ridge events? STAR Preliminary  -  results

26. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi26 | η trig |<1 3<p T trig <10 GeV/c 2.7<| η assoc |<3.9 0.2<p T assoc < 2 GeV/c

27. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi27 Trigger: MTPC: 3<p T trig <4 GeV/c, Associated: FTPC: 0.2<p T assoc < 2 GeV/c, MTPC: 0.2<p T assoc < 3 GeV/c pp MB dAu MB AuAu 60-80% AuAu 0-10% AuAu 0-5%

28. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi28 PHENIX preliminary Identified  0 trigger with associate hadron Width does not change with centrality similar to charged hadron triggered case. 7-9 (X) 1-2 0-20% 7-9 (X) 4-5 0-20% 7-9 (X) 4-5 20-40% 7-9 (X) 4-5 40-60% 7-9 (X) 4-5 60-90% 7-9 (X) 6-8 40-60% QM08 PHENIX

29. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi29 1/Ntrig dN/d  (A.U.) p T, photon GeV Per-Trigger Yield (A.U.) Run 6 p+p @ 200 GeV 0 Run 7 Au+Au @ 200 GeV, cent=0~20%, preliminary Direct  trigger with associate hadron QM08 PHENIX p+p: Consistent with trigger photon carrying the full jet energy, away side jets are similar between  0 and  triggers. Need more studies and statistics for Au+Au case. Run 4/5 p+p/Au+Au @ 200 GeV

30. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi30 3<p T trig <4GeV/c & 1.0<p T asso <1.5GeV/c 20-60% STAR  =  associate -  trigger (rad) Jet modification and geometry (and v 2 ) QM08: STAR, PHENIX QM04: STAR Mach-cone shape depends on R.P. angle. Mach-cone is a source of of v 2

31. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi31 STAR Preliminary Ridge Jet 3<p T trig <4, 1.5<p T trig <2.0 GeV/c QM08 STAR STAR  (rad)  Ridge “jet” Au+Au, 200 GeV Ridge/Cone and geometry (v 2 ) Ridge shape depends on R.P. angle. Ridge is a source of of v 2 Jet does not depends on it Jet reduces v 2 Jet Ridge Shoulder (cone) Head (  ) Ridge Shoulder (cone)   v2v2 v2v2

32. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi32  (rad)  PYTHIA p+p trigger near side away side y x  (1)away side of a back-to-back(b-t-b) jet is wider in  than in  (2)If there are two parallel b-t-b jets, away side of one b-t-b jet can be near side of the another b-t-b jet. (3)Suppression as well as modification of b-t-b jet would depend on relative angle w.r.t. almond geometry, we know this from v 2 measurement and believe this is the major source of v 2 at high p T. (4)Therefore, there should be inter b-t-b jets correlation give by the geometry from (3), this could make near side ridge like effect, especially if the effect (3) has shaper dependence than v 2 (=cos2x). (5)We always measure inclusive v 2, which includes the effect (3). Therefore any modification which could generates the elliptic anisotropy would be included in the measured v 2. (6)We subtract BG contribution with this v 2 from (5) by maximizing BG contribution assuming zero jet yield at minimum at any d . (7)If near and away side jets overlap each other, this subtraction underestimates the jet yield and can change the extracted jet shape. (8)If you extract angular dependence of jet w.r.t. R.P., the results will easily be affected by the choice of v 2 from (5).

33. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi33 AMPT 200GeV Au+Au → charged hadrons (|y|<2.0) string-melting 10mb string-melting 3mb default AMPT 3mb b = 12 fm ~b = 8~12 fmb = 4~8 fmb = 0~4 fm 1/N trig. dN asso. /d|  trig. -  asso. | |  trig. -  asso. | (rad) p T asso. : 0.7-1.7GeV/c p T trig. : 1.7-4GeV/c

34. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi34 AMPT 200GeV Au+Au → charged hadrons (|y|<2.0) p T asso. : 0.7-1.7GeV/c p T trig. : 1.7-4GeV/c trigger at in-plane average trigger at out-of-plane b = 12 fm ~b = 8~12 fmb = 4~8 fmb = 0~4 fm |  trig. -  asso. | (rad) 1/N trig. dN asso. /d|  trig. -  asso. |

35. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi35 (1) (2) (3) (4) (2) (3) (4) (1) Trigger particle x(R.P.) yy     (2) Trigger particle  ASSO.  TRIG. associate particle direction at same |  | w.r.t. trigger particle but with different arrow length associate particle direction at same |  | w.r.t. red dashed line but with different arrow length  In order to study the jet modification (mach-cone, ridge) and it’s relation with almond geometry in more detail… with and without R.P. aligned event mixing

36. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi36 AMPT 200GeV Au+Au default option melting-on 0~9% 9~19% 19~39% 39~100% (1)(2) (3) (4)(all) (1)(2) (3) (4)(all) 0~9% 9~19% 19~39% 39~100%

37. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi37

38. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi38 Summary and Conclusion ・ 2- and 3- particle correlation and transverse momentum dependence of jet-modification tells us that it is likely a mach-cone. ・ Mach-cone and ridge are almost as soft as inclusive particles. ・ Identified particle (baryon, meson,  0,  ) correlation measurements. ・ Mach-cone and ridge w.r.t. reaction plane angle tells us that this is a part of v 2

39. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi39 Extra and Back-up Slides

40. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi40 PRC71 051902 2.4<p T Trig <4 GeV/c 1.7< p T Asso <2.5 GeV/c Identified Baryon/Meson trigger with associate hadron Enhanced near-side yield can not be explained by soft process like thermal recombination alone.

41. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi41 R.P. (1) (2) (3) (4) (5) (6) (7) (8) ave (1)~(8) ave (1),(8)ave (2),(7)ave (3),(6)ave (4),(5) (1)(2)(3)(4)(8)(7)(6)(5) Pure Flow Simulation with trigger angle selection w.r.t. R.P. with/without R.P. aligned event mixing without R.P. aligned event mixing with R.P. aligned event mixing (1)(2)(3)(4)(8)(7)(6)(5)

42. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi42 Au+Au vs. Cent @  /4 Au+Au vs. RP Inclusive Au+Au Inclusive correlation Au+Au – Example: 0-5% –Modest flow in this bin –Background subtraction can only make effect more pronounced Choose a trigger orientation with minimal impact from modulated background –4 th bin: ~  /4 (grey circles) Example: Au+Au in 4 th RP bin, several centralities –“mach cone”(?) effect clear without any subtraction –Need to focus on source of shoulder! Medium effects w/o subtraction?

43. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi43

44. KEK seminar, 5/Nov/2008Univ. of Tsukuba, ShinIchi Esumi44