1 / 31

In-Medium Properties of Hadrons

Jets. Berkeley School of Collective Dynamics in Honor of Gerry Brown. In-Medium Properties of Hadrons. Experimental Search for Mach Shock Conical Flow. Fuqiang Wang. Outline. Physics motivations How Mach cone comes into the picture

sebastian-mckenzie
Download Presentation

In-Medium Properties of Hadrons

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. Jets Berkeley School of Collective Dynamics in Honor of Gerry Brown In-Medium Properties of Hadrons Experimental Search for Mach Shock Conical Flow Fuqiang Wang

  2. Outline • Physics motivations • How Mach cone comes into the picture • How to observe it: 3-particle jet-like correlation results • Summary The Berkeley Gerry Brown School – Fuqiang Wang

  3. p+p Au+Au hadrons q q q q well calibrated: can be calculated by pQCD. well calibrated: can be calculated by pQCD. leading particle leading particle hadrons hadrons q q q q hadrons hadrons leading particle leading particle Motivation: Probing Heavy-Ion Medium by Jets • Hard-scattering between partons in pp. • Fragmentation of partons produce back-to-back jets of hadrons. • Jets are clustered in angle and rich in high-pt particles. • Jets produced in AA traverse and interact with the medium, lose energy and thus carry information of the medium. The Berkeley Gerry Brown School – Fuqiang Wang

  4. Au+Au hadrons q q well calibrated: can be calculated by pQCD. leading particle hadrons pTtrig=4-6 GeV/c, pTassoc=0.15-4 GeV/c pTtrig>4 GeV/c, 2<pTassoc<4 GeV/c q PRL95 (2005) 152301 q hadrons AA over binary-scaled pp leading particle Motivation: Probing Heavy-Ion Medium by Jets leading particle suppressed away-side particles enhanced at low pT away-side particles suppressed at high pT The Berkeley Gerry Brown School – Fuqiang Wang

  5. Au+Au hadrons M. Horner, QM06. q q well calibrated: can be calculated by pQCD. leading particle hadrons pTtrig=4-6 GeV/c, pTassoc=0.15-4 GeV/c q F.Wang (STAR), QM’05, nucl-ex/0510068. PRL95 (2005) 152301 q hadrons Away side <pT> (GeV/c) leading particle Motivation: Probing Heavy-Ion Medium by Jets pTtrig=3-4 GeV/c, pTassoc=1-2.5 GeV/c center part does not drop. hump increases with centrality. shock wave excitation? away-side particles enhanced at low pT double-hump is harder: shock wave push? The Berkeley Gerry Brown School – Fuqiang Wang

  6. near-side trigger projection assoc. hadrons Df Df away-side jet axis Mach cone shock waves? Scheid, Muller, Greiner, Phys. Rev. Lett. 32, 741 (1974); Hofmann, Stoecker, Heinz, Scheid, Greiner, PRL 36, 88 (1976). Many recent studies: Stoecker, nucl-th/0406018; Casalderrey-Solana, Shuryak, Teaney, hep-ph/0411315; Ruppert, Muller, hep-ph/0503158; Chaudhuri, Heinz, nucl-th/0503028; Renk, Ruppert, PRC73 (06) 011901, Y.G. Ma, et al., nucl-th/0601012. … Perfect fluid of hot and dense matter at RHIC: cS, supersonic jets, jet-quenching. RHIC appears to have all the conditions to generate Mach-cone shock waves. The Berkeley Gerry Brown School – Fuqiang Wang

  7. length x 1016 time x 1022 3cSDt 2cSDt cSDt qM zone ofaction 2 1 0 v > cS zone of silence Why is it important? Casalderrey-Solana, Shuryak, Teaney, hep-ph/0411315 Mach cone angle qM speed of sound cS = sin(qM) equation of state The Berkeley Gerry Brown School – Fuqiang Wang

  8. Shock wave searches in AA collisions The Berkeley Gerry Brown School – Fuqiang Wang

  9. near Medium away preferential selection of jet particles: those directed inwards are harder to get out because of energy loss. well confined in each event but deflected at varying angle. Rudy Hwa deflected jets high pT parton other scenarios Double-peak structure can also be generated by large angle gluon radiation: Vitev, Phys. Lett. B630 (2005) 78 A.D. Polosa and C.A. Salgado, PRC75, 041901R (2007). or deflected jets: Armesto, Salgado, Wiedemann, PRL93, 242301 (2004) The Berkeley Gerry Brown School – Fuqiang Wang

  10. near near near Δ2 Δ2 Trigger π π Δ1 Δ2 Medium Medium Medium away away 0 0 π away π Δ1 Δ1 0 0 di-jets Δ2 π 0 deflected jets π Δ1 0 mach cone discrimination by 3-particle correlation Need 3-particle correlation to discriminate different physics mechanisms. The Berkeley Gerry Brown School – Fuqiang Wang

  11. jet trigger pTtrig=3-4 GeV/c pTassoc=1-2 GeV/c bkgd Δf2 Δ1 assoc.2 assoc.1 3-particle correlation backgrounds Jason Ulery (STAR), HP’06, nucl-ex/0609047; J.G. Ulery, FW, nucl-ex/0609016. Jason Ulery (STAR), QM’06 poster, arXiv:0704.0224 [nucl-ex] . raw = (jet+bkgd) x (jet+bkgd) jet x jet = raw – (bkgd x bkgd) – (jetx bkgd) 1/Ntrig d2N/dDf1dDf2 Δ2 Δ1 jetx bkgd bkgd x bkgd - + trigger flow trigger flow The Berkeley Gerry Brown School – Fuqiang Wang

  12. pp d+Au Au+Au 50-80% Au+Au 30-50% Au+Au central 0-12% ZDC Δ2 Δ2 π Au+Au 10-30% Au+Au 0-10% Δ1 0 π Δ1 0 3-particle correlation signal J.G. Ulery (STAR), HP’06, nucl-ex/0609047; C. Pruneau (STAR), QM’06, nucl-ex/0703010; Jason Ulery (STAR), QM’06, 0704.0224. pTtrig=3-4 GeV/c, pTassoc=1-2 GeV/c 1/Ntrig d2N/dDf1dDf2 Elongation along away diagonal: kT broadening, deflected jets. Evidence of conical emission in central Au+Au collisions. The Berkeley Gerry Brown School – Fuqiang Wang

  13. Conical emission signal in central Au+Au. Other contributions (such as deflected jets) present. projection along off-diagonaldiagonal 1/Ntrig d2N/dDf1dDf2 1/Ntrig dNtriplet/dDf Au+Au central 0-12% ZDC =(1+2)/2 =(1-2)/2 Δ2 1/Ntrig dNtriplet/dDf Δ1 =(1-2)/2 =(1+2)/2-p ZDC central 12% Au+Au Major sources of systematic errors: flow, background normalization. The Berkeley Gerry Brown School – Fuqiang Wang

  14. Au+Au 0-12% ZDC cone angle (radians) Δ2 (Npart/2)1/3 Δ1 Au+Au ZDC 12% Au+Au 0-50% cone angle (radians) pTassoc (GeV/c) Cone angle Jason Ulery (STAR), QM’06 poster, arXiv:0704.0224 [nucl-ex] 1/Ntrig d2N/dDf1dDf2 Cone angle consistent with no pT dependenc  Conical emission consistent with Mach-cone shock waves, notsimple Cerenkov gluon radiation. Cone angle: q ~ 1.45 ~ 80o cos(q) ~ 0.12 =??? cS The Berkeley Gerry Brown School – Fuqiang Wang

  15. Au+Au 0-12% ZDC Δ2 Δ1 3-particle signal strength J.G. Ulery (STAR), HP’06, nucl-ex/0609047; J.G. Ulery (STAR), QM’06, arXiv:0704.0224. Cone signal in pp, d+Au, peripheral Au+Au consistent with zero; increases rapidly in central Au+Au. 1/Ntrig d2N/dDf1dDf2 Away Cone Deflected + Cone signal / radian2 (Npart/2)1/3 The Berkeley Gerry Brown School – Fuqiang Wang

  16. reaction plane v2 + = 4-particle cumulant v2 Flow systematics Jason Ulery (STAR), Hard Probes 2006. • Flow is varied between the modified reaction plane result and the 4- particle cumulant result. • Result is robust with the variation in v2. The Berkeley Gerry Brown School – Fuqiang Wang

  17. Background normalization systematic default • Normalization within |Δ±1|<0.175 assuming zero yield at minimum. • Default uses a normalization range of 0.35. • Normalization range of 0.70 used to check systematic. • Result is robust with respect to normalization range. Jason Ulery (STAR), Hard Probes 2006. wide norm. region The Berkeley Gerry Brown School – Fuqiang Wang

  18. v2(jet) = v2(trig) v2(jet) = 0 Δ2 Filled: v2(jet) = v2(trig) Open: v2(jet) = 0 Au+Au 0-12% Δ1 (1+2)/2 (1+2)/2 (1+2)/2 (1-2)/2 (1-2)/2 (1-2)/2 The Berkeley Gerry Brown School – Fuqiang Wang

  19. * * * * f q f Df 12 12 13 Same Side Away Side Assoc. pTs (2,3) _ = * q = PHENIX polar coord. analysis Hi pT(1) Polar plot along azimuth along radius Normal Jet

  20. PHENIX deflected and cone jet similations High pT(1) High pT(1) 2-particle Correlations matched Deflected jet sim Mach Cone sim 3-Particle di-jet correlations allow a distinction between different mechanistic scenarios !

  21. PHENIX 3-particle correlation result Total 3-particle jet correlation: Jet x Jet + (Jet x Bkgd + Bkgd x Jet) Radial section True 3-particle jet correlation: Jet x Jet Strong away side modification in both total and true 3-particle jet correlations

  22. PHENIX 3-particle correlation: S/B ratio Total 3-particle jet correlation: Jet x Jet + (Jet x Bkgd + Bkgd x Jet) PHENIX, PRL 97, 052301 (2006): True 3-particle jet correlation: Jet x Jet The Berkeley Gerry Brown School – Fuqiang Wang

  23. Au+Au hadrons q q Df2 Df1 Summary • Evidence of conical emission in central AA. • Consistent with Mach-cone shock waves. • Speed of sound? EOS?Cone angle q ~ 1.45 ~ 80ocos(q) ~ 0.12 =??? cS conical emission of back-side particles The Berkeley Gerry Brown School – Fuqiang Wang

  24. extra slides The Berkeley Gerry Brown School – Fuqiang Wang

  25. Au+Au 0-12% ZDC Δ2 ZDC Δ1 3-particle signal strength J.G. Ulery (STAR), Hard Probes 06, nucl-ex/0609047; QM’06 poster # 44. • Major sources of systematic errors: flow, background normalization. • Mach cone signal in central Au+Au collisions. • Contribution from deflected jets present. 1/Ntrig d2N/dDf1dDf2 The Berkeley Gerry Brown School – Fuqiang Wang

  26. Same Side Away Side polar coord. analysis N.N. Ajitanand (PHENIX), poster # 39. • Background from mixed-events. • Background subtracted. • 3-particle correlation in PHENIX acceptance, consistent with MC. The Berkeley Gerry Brown School – Fuqiang Wang

  27. jet bkgd STAR 3-Particle Cumulant C. Pruneau (STAR), QM’06, nucl-ex/0703010 • Clear evidence for finite 3-Part Correlations • Observation of flow like and jet like structures. • Evidence for v2v2v4 contributions The Berkeley Gerry Brown School – Fuqiang Wang

  28. 3-Cumulant vs. centrality C. Pruneau (STAR), QM’06, nucl-ex/0703010 Au + Au 80-50% 30-10% 10-0% • kT? Interplay of jet & flow? The Berkeley Gerry Brown School – Fuqiang Wang

  29. toy model simulations Marco van Leeuwen, Hard Probes 2006. Cone case kTcase ZYAM/Purdue normalisation 4-peak structure for conicalemission 2-peak for kT-smearing Cumulant normalisation Valleys and peaks due to different normalisation 4-peak/2-peak difference also visible Valley-peak strength similar: 0.2 in both cases Signal seen in both schemes. Both schemes distinguish between conical emission and kT effect Caveat: soft-soft term ignored (see next slides) The Berkeley Gerry Brown School – Fuqiang Wang

  30. cumulant vs jet-like with no flow J.G. Ulery, FW, nucl-ex/0609017. The Berkeley Gerry Brown School – Fuqiang Wang

  31. cumulant vs jet-like with flow J.G. Ulery, FW, nucl-ex/0609017. The Berkeley Gerry Brown School – Fuqiang Wang

More Related