Presentation on theme: "MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 1/78 Have we found the Quark Gluon Plasma at RHIC? Experimental evaluation by the PHENIX Collab. M. J. Tannenbaum."— Presentation transcript:
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 1/78 Have we found the Quark Gluon Plasma at RHIC? Experimental evaluation by the PHENIX Collab. M. J. Tannenbaum Brookhaven National Laboratory Upton, NY 11973 USA Seminar, ETH Zurich October 19, 2004 PHENIX Collaboration See nucl-ex/0410003
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 2/78 High Energy Nucleus-Collisions provide the means of creating Nuclear Matter in conditions of Extreme Temperature and Density At large energy or baryon density, a phase transition is expected from a state of nucleons containing confined quarks and gluons to a state of “deconfined” (from their individual nucleons) quarks and gluons covering a volume that is many units of the confinement length scale.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 3/78 The Quark Gluon Plasma (QGP) The QCD confinement scale---when the string breaks---is order: 1/ QCD ~1/m =1.4 fm With increasing temperature, T, in analogy to increasing Q 2, s (T) becomes smaller, reducing the binding energy, and the string tension (T) becomes smaller, increasing the confinement radius, effectively screening the potential V= -4 s + r -4 s e - (T) 3 r For r 1/ the quark is free of the potential, effectively deconfined
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 4/78 The Quark Gluon Plasma (QGP) The state should be in chemical (particle type) and thermal equilibrium ~T The major problem is to relate the thermodynamic properties, Temperature, energy density, entropy of the QGP or hot nuclear matter to properties that can be measured in the lab.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 5/78 The gold-plated signature for the QGP J/ Suppression QGP In 1986, T. Matsui & H. Satz PL B178, 416 (1987) said that due to the Debye screening of the color potential in a QGP, charmonium production would be suppressed since the cc-bar couldn’t bind. This is CERN’s claim to fame: but the situation is complicated because J/ are suppressed in p+A collisions. [NA50 collaboration, M.C. Abreu, et al., PLB 477, 28 (2000)]
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 9/78 What is PHENIX? PHENIX = Pioneering High Energy Nuclear Interaction eXperiment A large, multi-purpose nuclear physics experiment at the Relativistic Heavy-Ion Collider (RHIC): 1 A 197. For Au+Au: 19 s NN 200 GeV L max = 2 x 10 26 cm -2 s -1 two independent rings ---> p+Au, d+Au, etc.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 10/78 How to discover the QGP The Classical road to success in RHI Physics: J/ Suppression Major background for e detection is photons and conversions from 0. but more importantly Need an electron trigger for full J/ detection EMCal plus electron ID at trigger level. High p T 0 and direct production and two-particle correlations are the way to measure hard- scattering in RHI collisions where jets can not be detected directly---> segmentation of EMCal must be sufficient to distinguish 0 and direct up to 25 GeV/c (also vital for spin) Charm measurement via single e (Discovered by CCRS experiment at CERN ISR)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 11/78 “Mike, is there a `real collider detector’ at RHIC?---J. Steinberger ” PHENIX is picturesque because it is not your father’s solenoid collider detector Special purpose detector designed and built to measure rare processes involving leptons and photons at the highest luminosities.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 12/78 EMCAL MuID MuTrk RICH PCs TEC/TRD DC TOF BBCMVD ZDC/SMD NTC FCAL Annotated View
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 13/78 hh (0)(0) Detecting electrons means detecting all particles=PHENIX EMC Energy / Momentum All charged tracks Background Net signal Real Apply RICH cut ElectroMagnetic Calorimeter measures Energy of photons and electrons reconstructs 0 from 2 photons. Measures decent Time of Flight hadrons deposit Minimum Ionization, or higher if they interact For electron ID require RICH (cerenkov) and matching energy in EMCal momentum +TOF=charged particle ID High Resolution TOF completes the picture giving excellent charged hadron PID Electron and photon energy can be matched to < 1%--No nonlinearity problem
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 14/78 PHENIX EMCal Lead-Scintillator (PbSc) Module Lead-Glass (PbGl) Super Module PbSc SectorPbGl Sector 6 PbSc sectors (15,552 channels) 2 PbGl sectors (9,216 channels) = 0.38 = 8 22.5 0 =180 0 Granularity ( ) 0.011 0.0110.008 0.008 System Energy resolution (%) Position resolution, orthog. imp. (mm) Timing resolution t 340 ps600ps BNL/PHENIXWA80/98 6 PbSc sectors2 PbGl sectors separates 0 and direct up to >25 GeV/c
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 15/78 The PHENIX detector 2 Central Tracking arms 2 Muon arms Beam-beam counters Zero-degree calorimeters (not seen)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 16/78 Charged particle tracking: Drift chamber Pad chambers (MWPC) Particle ID: Time-of-flight (hadrons) Ring Imaging Cherenkov (electrons) EMCal ( , 0 ) Time Expansion Chamber Acceptance: | | < 0.35 – mid-rapidity = 2 90 Detectors in the central spectrometer arms (pseudorapidity | | < 0.35) Charged Particle Tracking: Drift-Chambers (DC) Pad-Chambers (PC) Identification of charged hadrons: Time-of-Flight (TOF) with start signal from the Beam- Beam-Counters (BBC) Electron Identification Ring Imaging Cherenkov Detector (RICH) 0 via 0 Lead scintillator calorimeter (PbSc) Lead glass calorimeter (PbGl)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 17/78 Example of a central Au+Au event at s nn =200 GeV
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 18/78 Run Year Species s 1/2 [GeV ] Ldt N tot p-p Equivalent Data Size 01 2000 Au+Au 130 1 b -1 10M 0.04 pb -1 3 TB 02 2001/2002 Au+Au 200 24 b -1 170M 1.0 pb -1 10 TB p+p 200 0.15 pb -1 3.7G 0.15 pb -1 20 TB 03 2002/2003 d+Au 200 2.74 nb -1 5.5G 1.1 pb -1 46 TB p+p 200 0.35 pb -1 6.6G 0.35 pb -1 35 TB 04 2003/2004 Au+Au 200 241 b -1 1.5G 10.0 pb -1 270 TB Au+Au 62 9 b -1 58M 0.36 pb -1 10 TB Run-1 Run-2 Run-3 Run-1 to Run-4 Capsule History
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 19/78 Schematic Au+Au collision
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 20/78 Collision Centrality Determination Centrality selection : Sum of Beam-Beam Counter (BBC, | |=3~4) and energy of Zero-degree calorimeter (ZDC) Extracted N coll and N part based on Glauber model. Spectators Participants 0-5% 5-10% 10-15% Peripheral Central
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 21/78 N charged, E T exhibit(&could determine) the Nuclear Geometry Define centrality classes: ZDC vs BBC Extract N participants: Glauber model b N ch ETET E ZDC Q BBC N ch PHENIX ETET
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 22/78 Is the energy density high enough? PRL87, 052301 (2001) R2R2 2c Colliding system expands: Energy to beam direction per unit velocity || to beam 4.6 GeV/fm 3 (130 GeV Au+Au) 5.5 GeV/fm 3 (200 GeV Au+Au) well above predicted transition! EMCal measures Bj
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 23/78 Spacetime evolution is important
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 24/78 My best bet 1998-after BDMPS
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 25/78 Bjorken Scaling in Deeply Inelastic Scattering and the Parton Model---1968 Phys. Rev. 179, 1547 (1969) Phys. Rev. 185, 1975 (1969)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 26/78 BBK 1971 S.M.Berman, J.D.Bjorken and J.B.Kogut, Phys. Rev. D4, 3388 (1971) BBK calculated for p+p collisions, the inclusive reaction A+B C + X when particle C has p T >> 1 GeV/c The charged partons of DIS must scatter electromagnetically “which may be viewed as a lower bound on the real cross section at large p T.”
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 27/78 CCR at the CERN-ISR Discovery of high p T production in p-p e -6pT breaks to a power law at high p T with characteristic s dependence Large rate indicates that partons interact strongly (>> EM) with other. Data follow BBK scaling but with n=8!, not n=4 as expected for QED F.W. Busser, et al., CERN, Columbia, Rockefeller Collaboration Phys. Lett. 46B, 471 (1973) Bj scaling BBK scaling
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 28/78 BBK scaling with n=8, not 4 Inspires Constituent Interchange Model Berman, Bjorken, Kogut, PRD4, 3388 (1971) x T =2p T / s n=4 for QED or vector gluon n=8 for quark-meson scattering by the exchange of a quark CIM-Blankenbecler, Brodsky, Gunion, Phys.Lett.42B,461(1972)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 29/78 CCOR 1978--Discovery of “REALLY high p T >7 GeV/c” at ISR CCOR A.L.S. Angelis, et al, Phys.Lett. 79B, 505 (1978) See also A.G. Clark, et al Phys.Lett 74B, 267 (1978) Agrees with CCR, CCRS (Busser) data for p T < 7 GeV/c. Disagrees with CCRS fit pT > 7 GeV/c New fit is:
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 30/78 n(x T, s) WORKS n 5=4 ++ Same data Ed 3 /dp 3 (x T ) ln-ln plot QCD: Cahalan, Geer, Kogut, Susskind, PRD11, 1199 (1975)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 31/78 ISR Expt’s more interested in n(x T, s) than absolute cross section cross sections vary by factor of 2 Athens BNL CERN Syracuse Collaboration, C.Kourkoumelis, et al Phys.Lett. 84B, 279 (1979) But n(x T, s) agrees
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 32/78 RHIC pp spectra s=200 GeV nicely illustrate hard scattering phenomenology 00 Good agreement with NLO pQCD this is no surprise for `old timers’ (like me) since as I just explained, single particle inclusive spectra were what proved QCD in the late 1970’s before jets. Reference for A+A and p+A spectra 0 measurement in same experiment allows us the study of nuclear effect with less systematic uncertainties. PHENIX (p+p) PRL 91, 241803 (2003) Hard Scattering p-p Thermally- shaped Soft Production
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 33/78 -A DIS at AGS (1973)--Hard-Scattering is pointlike -A DIS at AGS (1973)--Hard-Scattering is pointlike
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 34/78 High p T in A+B collisions---T AB Scaling view along beam axis For point-like processes, the cross section in p+A or A+B collisions compared to p-p is simply proportional to the relative number of pointlike encounters A for p+A, AB for A+B for the total rate T AB the overlap integral of the nuclear profile functions, as a function of impact parameter b looking down
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 35/78 What really Happens for p+A: R A > 1! The anomalous nuclear enhancement a.k.a. the Cronin effect-- due to multiple scattering of initial nucleons (or constituents) Known since 1975 that yields increase as A , > 1 J.W. Cronin et al., Phys. Rev. D11, 3105 (1975) D. Antreasyan et al., Phys. Rev. D19, 764 (1979)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 36/78 The Nuclear Modification Factor R AB is the ratio of pointlike scaling of an A+B measurement to p-p Compare A+B to p-p cross sections Nuclear Modification Factor: “Nominal effects”: R AB < 1 in regime of soft physics R AB = 1 at high-p T where hard scattering dominates AB AA AB
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 37/78 High p T physics PHENIX Year-1 High-p T Hadrons Hadron spectra out to p T ~4-5 GeV/c Nominally expect production through hard scattering, scale spectra from N+N by number of binary collisions Peripheral reasonably well reproduced; but central significantly below binary scaling
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 38/78 Run-1: RHIC Headline News … January 2002 THE major discovery at RHIC (so far) PHENIX First observation of large suppression of high p T hadron yields ‘‘ Jet Quenching’’? == Quark Gluon Plasma? PHENIX PRL 88, 022301 (2002)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 39/78 RHIC Run 2 s=200 GeV/c:1) 0 extend to higher p T in Au+Au collisions; 2) + 0 reference in p-p Au-Au nucl-ex/0304022 Phys. Rev. Letters 91, 072301 (2003) PHENIX Centrality
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 40/78 R AA ( 0 ) AuAu:pp 200GeV High p T Suppression flat from 3 to 10 GeV/c ! PRL 91, 072301 (2003) Binary scaling Participant scaling Factor 5 Large suppression in central AuAu - close to participant scaling at high P T Peripheral AuAu - consistent with N coll scaling (large systematic error)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 41/78 Suppression at RHIC s NN =130 GeV is unique in A+A collisions--Enhancement at lower s NN CERN: Pb+Pb ( s NN ~ 17 GeV), ( s NN ~31 GeV) plus all previous measurements in p+A in same x range A.L.S.Angelis PLB 185, 213 (1987) WA98, EPJ C 23, 225 (2002) PHENIX, PRL 88 022301 (2002) D.d'E. PHENIX Preliminary QM2002 N collision scaling N part scaling R AA ~ 0.4 R AA ~0.2 R AA ~ 2.0 R AA ~1.5 BCMOR Collab. Cronin Enhancement Initial state effect (p+A) only depends on x, final state in A+A could depend on s NN
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 42/78 Suppression: Final State Effect? Hadronic absorption of fragments: Gallmeister, et al. PRC67,044905(2003) Fragments formed inside hadronic medium Parton recombination (up to moderate p T ) Fries, Muller, Nonaka, Bass nucl-th/0301078 Lin & Ko, PRL89,202302(2002) Energy loss of partons in dense matter Gyulassy, Wang, Vitev, Baier, Wiedemann… See nucl-th/0302077 for a review.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 43/78 Alternative: Initial Effects Gluon Saturation (color glass condensate: CGC) Wave function of low x gluons overlap; the self-coupling gluons fuse, saturating the density of gluons in the initial state. (gets N ch right!) hep-ph/0212316; D. Kharzeev, E. Levin, M. Nardi Multiple elastic scatterings (Cronin effect) Wang, Kopeliovich, Levai, Accardi Nuclear shadowing r/ gg g D.Kharzeev et al., PLB 561 (2003) 93 Broaden p T
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 44/78 d+Au: Control Experiment to prove the Au+Au discovery The “Color Glass Condensate” model predicts the suppression in both Au+Au and d+Au (due to the initial state effect). The d+Au experiment tells us that the observed hadron suppression at high p T central Au+A is a final state effect. This diagram also explains why we can’t measure jets directly in Au+Au central collisions: all nucleons participate so charged multiplicity is ~200 times larger than a p-p collision 300 GeV in standard jet cone. Au+Au d+Au = cold medium = hot and dense medium Initial State Effects Only Initial + Final State Effects
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 45/78 Cronin effect observed in d+Au at RHIC s NN =200 GeV, confirms x is a good variable PHENIX preliminary 0 d+Au vs centrality for DNP2003
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 46/78 This leads to our second PRL cover, our first being the original Au+Au discovery
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 47/78 Theoretical Understanding? Both Au-Au suppression (I. Vitev and M. Gyulassy, hep-ph/0208108) d-Au enhancement (I. Vitev, nucl-th/0302002 ) understood in an approach that combines multiple scattering with absorption in a dense partonic medium Our high p T probes have been calibrated and are now being used to explore the precise properties of the medium Au-Au d-Au See nucl-th/0302077 for a review.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 48/78 Suppression: Final State Effect Energy loss of partons in dense matter--A medium effect predicted in QCD---Energy loss by colored parton in medium composed of unscreened color charges by gluon bremsstrahlung--LPM radiation Gyulassy, Wang, Vitev, Baier, Wiedemann… See nucl-th/0302077 for a review. Baier, Dokshitzer, Mueller, Peigne, Shiff, NPB483, 291(1997), PLB345, 277(1995), Baier hep-ph/0209038, From Vitev nucl-th/0404052: Bj =15 GeV/fm 3
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 49/78 Does the s NN =130, 200 GeV dependence of suppressed 0 follow QCD--x T scaling Peripheral 60 -- 80% Central 0-10% x T =2p T / s Berman, Bjorken, Kogut, PRD4,3388(1971) QCD: Cahalan, Geer, Kogut, Susskind, PRD11, 1199 (1975)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 50/78 Same data vs x T on log-log plot
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 51/78 n(x T ) point-by-point 200/130 0 x T scales in both peripheral and central Au+Au with same value of n=6.3 as in p-p (h + + h - )/2 x T scales in peripheral same as p-p but difference between central and peripheral is significant
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 52/78 The Discovery that was not predicted
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 53/78 protons at intermediate p T scale with Ncoll ?? spawned lots of good ideas---no satisfactory explanation
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 54/78 Charged Hadron excess 2.0 4.5 GeV/c at 200 Au+Au at s NN = 200 GeV 1) a clear violation of x T scaling 2) a measurement of E vs centrality nucl-ex/0308006 Au+Au at s NN = 200 GeV nucl-ex/0308006 PRC R AA SUSB BNL R AA (p T )=constant for p T > 4
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 55/78 Mathematically the suppression is equivalent to a shift in the spectrum due to energy loss. R AA (p T )=constant for p T > 4 d /p T dp T is p T -8.1
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 56/78 Estimate of E/p T from R AA vs centrality Nice---but nothing quantitative jumps out at me. Try other plots. 0.000 0.080 0.139 0.232 0.036 PHENIX Collab. PRC 69, 034910 (2004) nucl-ex/0308006 E/p T n=8.1
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 57/78 Plot E(p T )/p T =S loss vs centrality Bj (Npart) !
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 58/78 Flow is an interesting complication in collisions of nuclei
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 59/78
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 60/78 Measure R AA vs reaction plane
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 61/78 DirectPhotons --- 0 ( ) makes huge background- down a factor of 2/(n-1) due to falling spectrum
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 62/78 Actual calculated 0 +... / 0 Actual calculated 0 +... / 0 We do this because doing the same with the actual point by point and inclusive measurements will cancel many systematics Variations: Tagging Methods (reject pairs in mass window), Isolation Methods Remove inherent background so smaller ( expected backgrd Then we can compare measured with background … all decay background /
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 63/78 PHENIX Preliminary PbGl [ ] measured / [ ] background = measured / background Direct -- QM02 Central 0-10% AuAu 200 GeV Central 0-10% p p g q q
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 64/78 1 + ( pQCD direct x N coll ) / ( phenix pp backgrd x N coll ) 1 + ( pQCD direct x N coll ) / phenix backgrd Vogelsang NLO 1 + ( pQCD direct x N coll ) / phenix backgrd Vogelsang, m = 0.5, 2.0 PHENIX Preliminary PbGl / PbSc Combined AuAu 200 GeV Central 0-10% Theory curves include PHENIX expected background calculation based on : ( direct + exp. bkgd. ) / exp. bkgd. = 1 + ( direct / exp. bkgd. ) QM04 Results Central 0-10% WoW Need lots more statistics+systematics -”jet”+thermal photons+... & 0 both suppressed 0 suppressed not suppressed
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 65/78 NLO-pQCD calculation Private communication with W.Vogelsang CTEQ6M PDF. direct photon + fragmentation photon Set Renormalization scale and factorization scale pT/2,pT,2pT The theory calculation shows a good agreement with our result Confirms use of theoretical result as Au+Au comparison Opens the way for measurement of gluon spin structure function from A LL (Subtraction) Direct- measurement in s=200 GeV p-p
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 66/78 PHENIX / 0 ratio in s=200 GeV p-p Pi0 fit function y=20.3/pow(x,8.285) BBC related systematical error iscanceled out. PHENIX Preliminary / 0 note: / 0 ratio is ~ 5 times larger in central Au+Au!
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 67/78 Proof of principle of A LL measurement-- 0
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 68/78 Cartoon Jet Func. = Correl Func - flow 2-Particle correlations as the (only) way to measure jets in (Au+Au) collisions from the CERN-ISR: CCOR PLB97, 163 (1980) Jet properties given by widths and integrals of same and away-side peaks x E =p T cos( - )/p Ttrig x h = p T / p Ttrig p out 2 =x h 2 2 k Ty 2 z trig 2 + j Ty 2 + j Ty 2 p out 2 =x E 2 2 k Ty 2 + j Ty 2 + j Ty 2 p out =p T sin( - ) z trig = p Ttrig / p Tjet CCOR--Feynman,Field,Fox-1978 PHENIX--Rak,Tannenbaum-2004
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 69/78 DATA: CCOR NPB 209, 284 (1982) Paris1982-first measurement of QCD subprocess angular distribution using 0 - 0 correlations QCDQCDQCDQCD
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 70/78 Open Charm (via single e ) AuAu 130 GeV A first in RHI collisions and very interesting conversion 0 ee ee, 3 0 ee, 0 ee ee, ee ee ’ ee l main systematic errors (band) –pion spectra, ratio 0, ratio conversion/Dalitz (material) Need converter run PRL 88, 192303 (2002)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 71/78 Converter run separates photonic from non-photonic e From CCRS PLB53, 212 (1974) Discovery of direct e at the CERN-ISR (S.N.White’s thesis)
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 72/78 QM02 PHENIX AuAu 200 GeV charm via e ± e+e- e+e- Some data with 1.7 % X 0 converter added converter only affects photonic component converter effect is much greater at low p T, indicating relatively much larger photonic component at low p T relatively smaller phtonic (i.e. larger non-photonic) component at higher pT (i.e. charm) Reduced systematic erros.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 73/78 Single e p T distribution vs Centrality 200 GeV AuAu data compared to pp data Consistent with binary (pointlike) scaling charm is not suppressed Consistent with our 130 GeV Measurement PRL 88, 192303 (2002) Pp single electrons are rebinned
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 74/78 PHENIX J/Psi-->e + e - from AuAu 200 GeV are Inconclusive PHENIX collaboration and BNL/PHENIX group’s main goal for next 4 years is to make a conclusive measurement of J/Psi in Au+Au (then other systems). All other physics automatically follows. Coalescence Models Enhancement Binary Scaling Suppression Models Equiv 49.3M min bias(7.2/24 b -1 ), but triggered 13 6 events
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 75/78 PHENIX J/ B-d /dy and for p-p s=200 GeV are very nice! clear J/ signals in both central and forward arms expected mass resolutions Bd /dy and total cross section measured thanks to trigger First measurement of total at collider; first above ISR. p+p J/ +X at s NN = 200 GeV nucl-ex/0307019; submitted to PRL N J/ = 46 N J/ = 65
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 76/78 Comparison with Previous Data (and Models) good agreement with lower s data and phenomenological extrapolation color octet model (COM) p+p J/ +X at s NN = 200 GeV nucl-ex/0307019; submitted to PRL mean transverse momentum: =1.80 0.23 (stat.) 0.16 (sys.) GeV/c RHIC/PHENIX p-p measurement is respectable and instructive!
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 77/78 J/ Production--State of the Art NA50 CERN fixed target Pb+Pb s NN= 17.2 GeV > 250K dileptons
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 78/78 The Short Answer is: No irrefutable signal for deconfinement yet---but the final state at in Au+Au at RHIC has density of unscreened color charges 10 times larger than that of a nucleon---not describable in terms of color neutral objects
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 79/78 Backup
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 80/78 PHENIX J/ and Acceptance All we need is Luminosity central (electron) armsforward (muon) arms rapidity coverage 0.35 < y < 0.35 1.2 < y < 2.4 (north) -2.2 < y < -1.2 (south) J/ acceptance0.8 % of B ee (4 % of B ee in |y| < 0.5) 4.3 % of B per arm) acceptance B ee B ee J/ 1.7 % of B ee (5 % of B ee in |y| < 0.5) 3.0 % of B (per arm) J/ mass resolution 20 MeV105 MeV mass resolution 160 MeV180 MeV PHENIX has both level-1 and level 2 triggers that would allow us to operate right now at up to ~100 times, if not more, than the present luminisoty of RHIC in both Au+Au and p-p collisions, without further upgrade.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 81/78 So, do jet analysis in Au+Au Trigger: hadron with p T > 2.5 GeV/c Identify as baryon or meson Biased, low energy, high z jets! Plot of associated partners Count associated lower p T particles for each trigger “conditional yield” Near side yield: number of jet associated particles from same jet in specified p T bin Away side yield: jet fragments from opposing jet trigger 2 particle correlations near side < 90° Partner from same jet away side > 90° opposing jet
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 82/78 Subtract the underlying event CARTOON flow flow+jet dN N trig d includes ALL triggers (even those with no associated particles in the event) jet Underlying event is big! Collective flow causes another correlation in them: B(1+2v 2 (p T trig )v 2 (p T assoc )cos(2 )) associated particles with non-flow angular correlations -> jets! Treat as 2 Gaussians 1 combinatorial background large in Au+Au!
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 83/78 2 particle correlations Select particles with p T = 2.5-4.0GeV/c Identify them as mesons or baryons via Time-of-flight Find second particle with p T = 1.7-2.5GeV/c Plot distribution of the pair opening angles
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 84/78 jet partner equally likely for trigger baryons & mesons Same side: slight decrease with centrality. Larger partner probability than pp, dAu Away side: partner rate as in p+p confirms jet source of baryons! “disappearance” of away- side jet for both baryons and mesons intermediate p T baryons ARE from jets
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 85/78
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 86/78 Are upper edge fluctuations random? Are upper edge fluctuations random? Event-by-event average p T (M pT ) is closely related to E T compare Data to Mixed events for random. deviation expressed as: Fp T = MpTdata / MpTmixed -1 ~ few % due to jets see nucl-ex/0310005
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 87/78 x E in pp collisions PHENIX preliminary CCOR (ISR) s = 63 GeV see A.L.S. Angelis, Nucl Phys B209 (1982) 284 Correct +- 1/ x E -5.3 =0.85 1/ x E -4 to –5 z trigg 1 / z = z trig / x E
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 88/78 pp and dAu correlation functions 3.0<p T <6.0 1.0<p T <1.5 Fit = const + Gauss(0)+Gauss( ) p+p h +- d+Au 5.0<p Ttrigg <16.0 GeV/c Near-side peak Fixed correlation: both p Ttrigg and p Tassoc are in the same range Assorted correlation: p Ttrigg and p Tassoc different Away side peak d+Au h 1.0<p T <1.5 1.5<p T <2.0 Jet function assumed to be Gaussian
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 89/78 From pp to dAu |k Ty | carries the information on the parton interaction with cold nuclear matter. |j Ty | should be the same as in pp – systematic cross check pp
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 90/78 |k Ty | from pp and dAu z =0.75 value taken from pp data k T -broadening increases with p Ttrig as as at lower s no difference in dAu and pp! need lots more data in both pp and p(d)+Au
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 91/78 AuAu: flow makes it much more complicated- Subtract far from near to cancel v 2 Subtracted dN/d integrating from 0-90, 90-180 to remove the v 2 component. (2.5 p Ttrigg 4.0) (1.0 p Tassoc 2.5) GeV/c Away jet reappears:it didn’t vanish, it broadened
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 92/78 AuAu |j Ty | and z trig |k Ty | pp (2.5 p Ttrigg 4.0) (1.0 p Tassoc 2.5) (3.0 p Ttrigg 5.0) (1.5 p Tassoc 3.0) There seems to be significant broadening of the away-side correlation peak which persists also at somewhat higher p T range. Need lots more statistics!
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 93/78 AuAu-PID meson or proton trigger no obvious difference Combinatoric background level determined by convolution of trigger and associated particle rate v2 values taken from PRL 91 (2003) 182301 modulates combinatoric level by 1+2v 2 (p T trig )v 2 (p T assoc )cos(2 ) (solid lines in plot) Trigger p T : 2.5-4.0GeV/c Associated p T : 1.7-2.5GeV/c
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 94/78 PHENIX Goals, Achievements and Plan with notable change in paradigm! Goal: To measures all possible signatures at once for proving QGP. Hadrons, leptons and photon. Accomplished baseline measurements by 3 RHIC runs. 22 publications (including e-print, as of Oct. 27. 2003) BNL/PHENIX group has leading role in 12 and important role in 4=16/22 Much remains: Truly rare probes in Au-Au Species & energy scans. Better statistics for correlaton measurements Conceptual Design Report (29-Jan-1993 )
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 95/78 PHENIX and E802 E T compared E877 dE T /d =200 GeV@ s NN =4.8 GeV PHENIX dE T /d ~680 GeV@ s NN =200 GeV PHENIX preliminary Are upper edge fluctuations in different size azimuthal regions random?
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 96/78 Fluctuation is a few percent of Mp T : Interesting variation with N part and p Tmax n >3 0.2 < p T < 2.0 GeV/c0.2 GeV/c < p T < p T max PHENIX nucl-ex/0310005 subm. PRL Errors are totally systematic from run-run r.m.s variations J.Mitchell (BNL) +BNLe-by-e
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 97/78 Jet Simulation Results PHENIX at s NN = 200 GeV The S prob x R AA parameter is initially adjusted so that F pT from the simulation matches F pT from the data for 20-25% centrality. 20-25% centrality
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 98/78 Estimate of the Magnitude of Event-by- Event Temperature Fluctuations Measurement s NN T / Most central T /, At the peak Fp T PHENIX2001.8%3.7% STAR1301.7%3.8% CERES171.3%2.2% NA49170.6%2.6% R. Korus and S. Mrowczynski, Phys. Rev. C64 (2001) 054908. See Jeff Mitchell’s QM2004 talk for more detailed comparisons of Expt’s
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 99/78 No tracking in B-field leads to background at high p T for charged particles DC low pT charged particle which decays low pT neutral particle which decays or converts vertex Example of miss- reconstruction from low p T charged decayed particle. Example of miss- reconstruction from low p T neutral decayed particle. Use EMCal to reject particles with E/p < 0.3 Use EMCal to reject particles with E/p < 0.3 plot by Maya SHIMOMURA
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 100/78 Comparison with 0 in d+Au
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 101/78 Analysis procedure (1) Prompt photon signal = All EMCal clusters – known components Signal / Noise = 0.2~1 (pT 5~17GeV/c) without 0 tag Non photon components (hadronic shower) Photon shower shape requirement Charged hadron veto with DC tracking Photon components 0 tag 0 without partner Photonic decay of non 0 ( , etc.) Estimated based on tagged as 0 Production * Br(h ) compared to 0 23 5% of all 0 contribution
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 102/78 Analysis procedure (2) R EE Isolation cut in this analysis Prompt photons = direct (qg qg) + fragmentation We expect that the isolation cut reduces the hadron backgrounds. In addition, it could separate photon production processes. Passes the isolation cut Only the fraction is survived Yes, it’s not so simple. (infrared divergences, underlying parton picture) In this analysis, we compare with/without the isolation cut without efficiency correction. With the subtraction method
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 103/78 0 tag Reason to miss the partner —Out of EMCal Arm —EMCal bad area —Less than the minimum E —Photon conversions —Photon merging Assign edges only for partner search (guard veto region) Careful definition Set E min at 150MeV (as low as possible). Charged veto with DC tracks, not with a detector in front of the EMCal In our pT region, those are rejected by the EM shower shape cut. Our efforts to recover them From MC, from missed 0 / from tagged 0 = 40% @ pT=5GeV/c = 20% @ pT=10GeV/c Now we are ready to obtain prompt photon yield.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 104/78 S/N ratio With Isolation Cut 0 tagging (subtraction) raw S: signal = all – ( 0, , etc. contributions) N: noise = all – signal – (tagged 0 ) With the isolation cut, The signal is enhanced.
MJT-Seminar-ETHZ-Oct 2004M. J. Tannenbaum 105/78 Does The Enhancement (R cp ) of pionsVanish At Higher p T ?? R CP Compares Yields in central and peripheral scaled by N coll Many systematics cancel Different parts of PHENIX measure different p T ranges of Enhancement in central vanishes at high p T BNL J.Jia (Columbia) +BNL Use EMCal to reject particles with E/p < 0.3 to eliminate fake high p T particles from decays & conversions Use EMCal to reject particles with E/p < 0.3 to eliminate fake high p T particles from decays & conversions