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p(d)A Physics in E866/NuSea and PHENIX

p(d)A Physics in E866/NuSea and PHENIX. Donald Isenhower - Abilene Christian University Isenhowe@acu.edu. DIS2003 25-April-2003 St. Petersburg, Russia. Review of E866 and results for pp total cross sections Future Drell-Yan? Plans are in place, but when and where?

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p(d)A Physics in E866/NuSea and PHENIX

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  1. p(d)A Physics in E866/NuSea and PHENIX Donald Isenhower - Abilene Christian University Isenhowe@acu.edu DIS2003 25-April-2003 St. Petersburg, Russia • Review of E866 and results for pp total cross sections • Future Drell-Yan? Plans are in place, but when and where? • Drell-Yan physics & Charmonium suppression in nuclei • Need for p(d)A results for AuAu physics • p(d)A physics in E866/NuSea & comparison to PHENIX • pT broadening & polarization • PHENIX muon system complete for Run 3 - news • Summary Donald Isenhower - ACU

  2. FNAL E866/NuSea Collaboration Abilene Christian University Donald Isenhower, Mike Sadler, Rusty Towell, Josh Willis Argonne National Laboratory Don Geesaman, Sheldon Kaufman, Bryon Mueller Fermi National Accelerator Laboratory Chuck Brown, Bill Cooper Georgia State UniversityGus Petitt, Xiao-chun He, Bill LeeIllinois Institute of Technology Dan KaplanLos Alamos National LaboratoryTom Carey, Gerry Garvey, Mike Leitch, Pat McGaughey,Joel Moss, Jen-Chieh Peng, Paul Reimer, Walt Sondheim New Mexico State University Mike Beddo, Ting Chang, Vassili Papavassiliou, Jason WebbOak Ridge National Laboratory Paul Stankus, Glenn YoungTexas A & M UniversityCarl Gagliardi, Bob Tribble, Eric Hawker, Maxim VasilievValparaiso UniversityDon Koetke Donald Isenhower - ACU E866/NuSea

  3. FNAL E866/NuSea • Forward xF, high-mass spectrometer • Solid Be, Fe, W and empty targets • Thick absorber wall to filter out all but m’s • Two acceptance defining magnets • Four tracking stations and one momentum analyzing magnet • Scale 60m long, 3m x 3m at back Donald Isenhower - ACU E866/NuSea

  4. DY Open Charm Randoms Donald Isenhower - ACU E866/NuSea

  5. E866/NuSea Donald Isenhower - ACU Ratios of measured Drell-Yan pp and pd cross sections to NLO based on MRST2001 E866/NuSea

  6. E866 Drell-yan cross sections per nucleon for selected xF bins Donald Isenhower - ACU E866/NuSea

  7. FNAL E866/NuSea Total Cross-section Measurments (PRL submitted and should appear soon, long PRD paper under preparation) • FNAL E866/NuSea has measured: • First extensive Drell-Yan double-differential cross sections in pp collisions • Most precise Drell-Yan cross sections in pd (or pA) collisions • Triply-differential cross sections in both pp and pd collisions over a broad kinematic range • These results demonstrate: • Recent NLO PDF fits provide a reasonable description of antiquark distributions for 0.02 < x < 0.25 • Recent NLO PDF fits may overestimate the valence quark distributions at large x • (for more on this, see Wu-Ki Tung’s talk at this conference) Donald Isenhower - ACU E866/NuSea

  8. Drell-Yan at Fermilab Main Injector Experiment has been approved by FNAL, but is not scheduled to run until 2007-08 • Advantages of 120 GeV Experiment • Larger Drell-Yan cross section, 7 times larger than at 800 GeV • Lower J/y background from beam dump, 7 times smaller • These will yield 50 times more events that E866/NuSea • Disadvantages: • Larger multiple scattering of lower energy muons • Poorer mass and x resolution • Increased single muon background from hadron decays • Shorten target absorber distance Donald Isenhower - ACU E866/NuSea

  9. JHF Letter of Intent Physics of High-Mass Dimuon Production at the 50 GeV Proton Synchrotron J.C. Peng et al. • What will be measured? • Unambiguous establishment of scaling violations in Drell-Yan process • Light anti-quark asymmetry via pp and pd • Nuclear effects via Drell -Yan • Partonic energy loss in nuclei • Quarkonium production • If polarized proton source: • 1. Transversity - correlation between quark momentum and its perpendular spin component • 2. Sea quark polarizations Donald Isenhower - ACU

  10. Donald Isenhower - ACU E866/NuSea

  11. FNAL E906 pA Experimental Program Measure ratio of Drell-Yan yields from d, C, Ca, and W Coverage of Anti-Shadowing and EMC effect regions Better large-x coverage than E772 Antiquark differences in the nucleus Donald Isenhower - ACU E866/NuSea

  12. E906 comparison to NMC, E139, and E886 Donald Isenhower - ACU E866/NuSea

  13. Peng et al, PLB 344 (1995) 1-5. DY  J/Y • J/y suppression – an effective signature of Quark-gluon plasma (QGP) formation? • Color screening in a QGP would destroy pairs before they can hadronize into charmonium • But ordinary nuclear effects also absorb or modify J/y’s • We need a comprehensive understanding of charmonium production in nuclei • Competing effects may be identified in p-A collisions by their strong kinematic dependencies, together with complementary studies of Drell-Yan scattering and open-charm production Donald Isenhower - ACU E866/NuSea

  14. Nuclear modification of parton level structure & dynamics Drell-Yan Drell-Yan Process Ratio(W/Be) 1.0 0.9 0.8 E866 R(W/Be) NMC DIS E772 R(W/D) 0.7 • Modification of parton momentum distributions of nucleons embedded in nuclei • e.g. shadowing – depletion of low-momentum partons. Process dependent? • Nuclear effects on parton “dynamics” • energy loss of partons as they propagate through nuclei • and (associated?) multiple scattering effects • Production of heavy vector mesons, e.g. J/y, y ',  • production: color singlet or octet ( ) and color neutralization timescale • hadronization time: • Coherence length for cc fluctuations: • absorption on nucleons or co-movers • feed-down from higher mass resonances, e.g. χc Donald Isenhower - ACU E866/NuSea

  15. E866/NuSea: 800 GeV p-A (Fermilab) PRL 84, 3256 (2000) open charm: no A-dep at mid-rapidity Hadronized J/Y? • J/y and y’ similar at large xF where they both correspond to a traversing the nucleus • but y’ absorbed more strongly than J/y near mid-rapidity (xF ~ 0) where the resonances are beginning to be hadronized in nucleus. • Scaling of J/y Suppression? • Comparison of 800 GeV (E866) and 200 GeV (NA3) -appears to scale only with xF Donald Isenhower - ACU E866/NuSea

  16. Correction to Nuclear Dependence for pT Acceptance • Incomplete coverage in pT can distort J/y suppression versus xF • E866/NuSea pT coverage is much better than previous experiment (e.g. E772) because of improved trigger • Most significant effects are at lowest xF where pT is cut off near 1 GeV/c • Use MC acceptance & ds/dpT consistent with our data to correct for incomplete coverage Donald Isenhower - ACU E866/NuSea

  17. PT broadening Summary • A universal phenomena seen with, e.g. p, p and beams. • is ~5 times larger for J/y than for Drell-Yan; cause? • gluons interact more strongly than quarks by 9/4 color factor • resonances can multiple scatter in final state • J/y grows with • Radiative energy loss associated with Drell-Yan pT broadening in the BDMS model is tiny Donald Isenhower - ACU E866/NuSea

  18. J.C.Peng, LANL Eskola, Kolhinen, Vogt hep-ph/0104124 PHENIX µ+µ- E866/NuSea e+e- PHENIX µ PHENIX e E866 (mid-rapidity) NA50 Kopeliovich, Tarasov, & Hufner hep-ph/0104256 Gluon Shadowing for J/y’s • In PHENIX µ acceptance for Au-Au collisions? • Eskola… : ~ 0.8 • Kopeliovich… : ~ 0.4 • Strikman…[hep-ph/9812322] : ~ 0.4 PHENIX µ+µ- (Au) Donald Isenhower - ACU E866/NuSea

  19. Arleo,Gossiaux,Gousset,Aichelin Model (PRC 61, 054906 (2000) & hep-ph/0105047) E866 data J/Y pre-resonance Y’ • Absorption of color-octet or –singlet with color neutralizaton times • J/Y, Y’ & cc with feed-down • Fit to E866/NuSea data with no shadowing & no dE/dx. fully-formed resonances PHENIX Muon Arms xF J/Y • p-Au at RHIC: Predictions • J/y & y’ differences at negative rapidity • Effect of dE/dx, also at negative rapidity w/o dE/dx R(Au/p) Y’ 200 GeV p+Au (RHIC) J/Y +dE/dx yCM yCM Donald Isenhower - ACU E866/NuSea

  20. “Model” R α No shadowing difference from fixed-target expt. 1 .92 Eskola… .66 .84 w/o anti-shadowing .75 .87 Kopeliovich… .4 .74 Gluon shadowing Gerland, Frankfurt, Strikman, Stocker & Greiner (hep-ph/9812322) 10 GeV Change due to shadowing for PHENIX μ relative to NA50 for different models to the W/H ratio (R) and the resulting effective α. 5 GeV Q = 2 GeV (Ratios due to gluon shadowing alone) Donald Isenhower - ACU E866/NuSea

  21. Parton Energy Loss in Nuclei – Kopeliovich Model Johnson, Kopeliovich et al., hep-ph/0105195 • Shadowing when coherence length, • is larger than nucleon separation • Three dE/dx mechanisms: • String breaking: dE/dz ~ Ks ~ 1 GeV/fm • Multiple bremstrahlung: • dE/dz ~ 3a /p <kT2> ~ .8 GeV/fm • Radiative gluon (BDMS): • DE ~ 3a /8 D<pT2><L> ~ .075 GeV/fm • (since <pT2> ~ 0.1 GeV2 from E772) • Total DE ~ 2 GeV/fm expected from above • From E866 DY data with separation of shadowing & dE/dx via Mass dependence, gives dE/dz ~ 3 ± .6 GeV/fm Shadowing dE/dx & Shadowing Drell-Yan data from E772 (PRL 64, 2479 (1990)) Donald Isenhower - ACU E866/NuSea

  22. Kopeliovich, Tarasov, Hufner hep-ph/0104256 E866 data • Model: • absorption • Dynamic calculation of shadowing and of energy loss • Also gluon anti-shadowing from Eskola Full calculation Donald Isenhower - ACU E866/NuSea

  23. Upsilon Polarization – E866/NuSea, Phys. Rev. Lett. 86, 2529 (2001) Y2S+3S DY Y1S Y1S Y2S+3S Y2S+3S DY Y1S • Y2S+3S has maximal polarization, • like Drell-Yan • Y1S has very small polarization Donald Isenhower - ACU E866/NuSea

  24. Part 2: PHENIX J/y measurement with muon arms in d-Au interactions at√ sNN = 200 GeV Donald Isenhower - ACU

  25. The Collaboration A strongly international venture: • 12 nations Brazil, China, France, Germany, Hungary, India, Israel, Japan, South Korea, Russia, Sweden, United States • 57 institutions Donald Isenhower - ACU

  26. The PHENIX Detector • e, , h (Central Arms) • || < 0.35,  =  • pT> 0.2 GeV/c •  (Muon Arms) • 1.2 < || < 2.4,  = 2 • ptot> 2 GeV/c • Interaction-trigger and vertex Detectors • Beam-Beam Counters (3.0 < || < 3.9) • Zero-Degree Calorimeters (|| > 6.2) • Normalization Trigger Counters (1.1 < || < 2.8) Donald Isenhower - ACU

  27. 35° 35° 2 Muon Trackers = 2x3 stations 2 Muon Identifiers = 2x5 planes South Arm: Began operations in 2001-2002 run. North Arm: Installed in 2002. Muon 12.5° 10.5° Magnet Muon Identifiers PHENIX Muon Arms Tracking Stations Acceptance : 1.2 < || < 2.4  Muon minimum momentum ~ 2 GeV/c Donald Isenhower - ACU

  28. MUON IDENTIFIER The South Muon Identifier Small panel Donald Isenhower - ACU Large panel

  29. Winding anode wires for a station 3 octant MUON TRACKER Station 2 octant under construction Installing a station 2 octant into the south magnet Donald Isenhower - ACU Station 3 octants already installed

  30. End view of Muon Tracker - South Donald Isenhower - ACU

  31. Side view of PHENIX detector North Muon Tracker is seen on the right partially exposed Donald Isenhower - ACU

  32. Physics Motivations for J/ measurements at RHIC • Heavy Ion Physics • Search for the signature of the Quark-Gluon Plasma. J/ yield in heavy ion collisions can be Suppresseddue to Debye color screening OR Enhanceddue to Recombination • Important to compare J/ yields inAu+Au, p+p(Run 2~)and d+Au (Run-3~) collisions to separate the normal nuclear effects • Spin Physics • First direct measurement of the gluon helicity distribution, G(x), in the proton using double-longitudinal spin asymmetries of the J/ production in polarized p+p collisions (Run-3~) • Understanding of the production mechanism is a key issue  unpolarized p+p data is useful (Run-2~) Donald Isenhower - ACU

  33. Need single muon measurement for open charm • Measure charm production by D meson semi-leptonic decay, • D K, in d Au collisions. • * Good normalization of J/ production. • * An important probe of the early stage of heavy ion reactions. • * Sensitive to the initial state gluon density in the nuclei. • It is difficult to reconstruct Ddirectly, instead we can • measure inclusive single muon spectrum. • Contributions to the single muon spectrum • a) Charm/Beauty decay. • b) Pion and Kaon decays - most dominant contribution, especially in low pT regime. • c) Other light mesons, such as , we believe their contributions are negligible. • d) Drell-Yan di-muons and thermal muons. • We consider Pion/Kaon decay contribution as background Donald Isenhower - ACU

  34. p+p  J/X cross sections Phys. Lett. B390,323 (1997) p+p,s=200GeV e+e- µ+µ- Rapidity Fit gives • Our result is consistent with s scaling from lower energy results Br (J/l+l-) (p+pJ/X) = 226  36 (stat.)  79 (syst.) nb  (p+pJ/X) = 3.8  0.6 (stat.)  1.3 (syst.) µb Donald Isenhower - ACU

  35. Preliminary results: South MUTR radiograph: Significant improvements in hardware and software and machine performance since then. Run-2 pp Donald Isenhower - ACU

  36. South MUTR: 2003 Gap-1 Gap-2 Gap-3 Sta-1 Sta-2 Sta-3 Run-3 (dAu): improved performance A new arm installed and operational ! North MUTR: Also, significant MUID and shielding improvements! Donald Isenhower - ACU

  37. Kinematics xF is defined as xF = 2*pz/sqrt(s). With the help of  = m2/s, we can obtain x1 and x2: x1 = 1/2*(xF+sqrt(xF2+4*)); x2= x1 - xF At the large s value of RHIC,  is small, as is therefore also x2. The x2 distributions are plotted for simulated J/'s. North CentralSouth Donald Isenhower - ACU

  38. South A subset of the data has been analyzed with online code. An order of magnitude improvement of the statistics in the peak should be expected in the real production pass. Trigger and detector eff. are not yet completely determined. Yield (counts) Donald Isenhower - ACU Mm+m-(GeV/c)

  39. North Note: not the same subset of the data as has been processed for the South arm. Direct comparisons between the yield in the two arms are thus meaningless for now. Yield (counts) Mm+m-(GeV/c) Donald Isenhower - ACU

  40. Summary of lessons from p(d)A • Charmonium suppression involves a non-trivial interplay between different effects and involves several timescales including that for hadronizaton and for the coherence of a pair. • It has large variations with xF and pT that help reveal the underlying mechanisms • p-A (or d-A) measurements serve as a basis for understanding what is seen in nucleus-nucleus collisions and are a must at RHIC. • Shadowing is certainly very important at RHIC and must be measured in d-A collisions as soon as possible Donald Isenhower - ACU

  41. 1. J/ peaks have been observed for both muon arms during dAu collisions in Run 3. 2. Production pass to analyze all Run 3 data is to be started RSN. Approximately an order of magnitude more data than presented here should be available. 3. Improving alignment will lead to improved mass resolution 4. Efforts are underway to determine trigger and detector efficiencies throughout the run. 5. Upcoming p-p run (Apr-May) will together with the dAu results also give a baseline for comparisons with the upcoming high statistics Au-Au (Nov -Jun) run. Summary and outlook for RHIC Run 3 Donald Isenhower - ACU

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