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PHENIX Beam Use Presentation W.A. Zajc for the PHENIX Collaboration

PHENIX Beam Use Presentation W.A. Zajc for the PHENIX Collaboration ( this talk available at http://www.phenix.bnl.gov/phenix/WWW/publish/zajc/sp/presentations/rbupaug02/PACAug02.htm ). Beam Use Proposal. Requested input: Desired “beam run segments” Physics from same

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PHENIX Beam Use Presentation W.A. Zajc for the PHENIX Collaboration

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  1. PHENIX Beam Use Presentation W.A. Zajc for the PHENIX Collaboration ( this talk available at http://www.phenix.bnl.gov/phenix/WWW/publish/zajc/sp/presentations/rbupaug02/PACAug02.htm )

  2. Beam Use Proposal Requested input: • Desired “beam run segments” • Physics from same • Collaboration/experiment status • A note on nomenclature: • “Run-1”  Summer-2000 Au-Au run at 130 GeV • “Run-2”  2001/2002 Au-Au/p-p at 200 GeV • “Run-3”  Upcoming (FY03) run

  3. Run Request at a Glance • Run-3 • d-Au: 16 weeks (10 weeks data-taking) • p↑-p↑: 8 weeks ( 3 weeks data-taking) • Run-4 • Au-Au: N weeks (definitive J/Y measurement) • p↑-p↑ : 26-N weeks ( DG measurement) • Run-5 • Si-Si: (Light ions with sufficient ∫L dt to measure J/Y) • p↑-p↑: (Towards 320 pb-1 at 200 GeV) • Notes: • Predicated on “Roser model”  3 modes deprecated • All running is assumed at √sNN = 200 GeV, with possible exception of development work towards 500 GeV for polarization

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

  5. Recent Additions • Peking University • Hungary • KFKI Research Institute for Particle and Nuclear Physics • Debrecen University • Elte University, Budapest • University of Colorado • University of Illinois Urbana-Champaign • Saha Institute / Jammu University (In progress)

  6. Run-1 Configuration • Two central arms • Mechanically ~complete • Roughly half of aperture instrumented • Global detectors • Zero-degree Calorimeters (ZDCs) • Beam-Beam Counters (BBCs) • Multiplicity and Vertex Detector (MVD, engineering run)

  7. Run-1 Publications (1) 1st study of dN/dh vs Npart • “Centrality dependence of charged particle multiplicity in Au-Au collisions at sNN = 130 GeV”,PRL 86 (2001) 3500 • “Measurement of the midrapidity transverse energy distribution from sNN = 130 GeV Au-Au collisions at RHIC”, PRL 87 (2001) 052301 • “Suppression of hadrons with large transverse momentum in central Au-Au collisions at sNN = 130 GeV”, PRL 88, 022301 (2002). • “Centrality dependence of p+/-, K+/-, p and pbar production at RHIC,”PRL 88, 242301 (2002). • “Transverse mass dependence of the two-pion correlation for Au+Au collisions at sNN = 130 GeV”, PRL 88, 192302 (2002) • “Measurement of single electrons and implications for charm production in Au+Au collisions at sNN = 130 GeV”,PRL 88, 192303 (2002) 1st measurement of ET 1st measurement of high pTsuppression 1st measurement of ‘high’ pT particle yields ‘1st’ measurement of source size at ‘high’ pT 1st measurement of open charm yields

  8. Run-2 (2001-2) From Run-1 to Run-2 Run-1 (2000) For 2001 Run:

  9. Run-2 Results • All central arm detectors instrumented and working • South Muon Arm commissioned; first physics • Implementation of Level-1 and Level-2 physics triggers • Dramatic extension of our reach in transverse momentum

  10. PHENIX at QM02 ≈ A Sample of ‘all’ Run-2 results

  11. Run-3 and Beyond

  12. DAQ and Trigger PHENIX has made a major effort to • Design and build a system capable of extracting all physics at design luminosity • Triggers commissioned, used in Run-2, extended for Run-3

  13. MUON IDENTIFIER LEVEL-1 TRIGGER • NIM Logic LVL-1 Trigger used during Run-2 • LVL-1 rejection is not required for Au+Au until RHIC significantly exceeds design luminosity. • LVL-1 rejection is required for lighter species, notably p+p and d+Au • Used for stand-alone cosmic ray (diagnostic) trigger • 4 gaps in trigger, each with 2 orientations. Trigger required hits in 6 out of 8 gap/orientations per quadrant. • ~60% efficiency (largely due to HV issues expected to be improved for Run 3) Use gaps 0,2,3,4. One MLU per quadrant.

  14. MUON LEVEL-2 TRIGGER • A steerable roadfinding trigger using MuID input • Available LVL-2 requirements: • minimum polar angle of muon(s) (12° or 15°) • opening angle between two muons • centrality of event (measured by PHENIX) • For Run-3: match to station 3 of the muon tracker • For Run-3: require minimum invariant mass of dimuon pair! • Efficient for muons from the vertex, good rejection of hadrons Measured rejection factors

  15. EmCal based PID • Now “routinely” usingTOF from EmCalto extend aperturefor our identified hadron analyses • Already in use forHBT • Will apply to f K+K-

  16. TEC  TRD upgrade • Time Expansion Chamber  Transition Radiation Detector • TRD upgrades: • Install radiators • Gas system • Previous: P-10 • TRD: • 50% Xe, 10-20% Methane40-30% He • Recirculation • General: • Previously: 4 planes • Now : 6 planes • End result: • Increased momentum resolution at high pT • Increased electron ID capability at high pT Electron Clusters Drift Window TR Photon TRD Radiator PUSH

  17. South Muon Arm Improvementsand North Muon Arm Commissioning • South Arm: • Replacement of muon tracker Glink-Clink cables • Muon tracker conformal coating added • North Arm: • Installed! • North muon tracker noise looks good • General: • Replacement of faulty muon identifier HV connectors • Muon identifier shielding • Expect improved performance for next run

  18. d-Au Segment • Assumptions • Duration • 2 weeks set-up • 3 weeks commissioning • 1 week studies (upper limit) • 10 weeks data-taking • Performance • 4 nb-1 week delivered during data-taking period • 20 cm rms vertex • d’s in blue ring • Physics questions addressed • Parton energy loss in ‘cold nuclear matter’ • J/Y production in nucleus over wide kinematic range • Open charm production and propagation • ~ “All” the usual soft physics • Dependence of above on number of participants (via gray tracks)

  19. TRIGGER RATE (Hz) Background Studies yellow target in • Purpose: • To understand any issues with Au ions in either ring • In preparation for anticipated high luminosity Au-Au in Run-4 • Needed due to • Different optics in each ring • Potential long lead time for any possible remedies • Up to 1 week requested • Results from Run-2 p-p run show benefit of • Collimating halo • Close collaboration with C-A D machine physicists blue target in collimate beam collimate blue collimator out dump yellow mis-steer TIME After * = 1 m achieved, significant non-collision background observed. Studied problem with help from RHIC during p+p running by mis-steering beam and seeing panel currents remain high. Rates very sensitive to beam scrape. Collimation helps tremendously. RHIC expects to further investigate and improve this situation.

  20. Muon Identifier Shielding • Prior preparation prevents previous ‘poor’ performance… Ready for Run 3 now. Special thanks to Charlie Pearson and C-A D. Initial approach to shielding: hand-stacked bars.

  21. PHENIX Preliminary pT dependent systematic error Q. Why did we build RHIC? A: To gain access to ‘small’ cross-sections* that are A) Fundamental B) Calculable C) Interesting which then allow us to use Ncoll ( aka “binary” or “point-like”) scaling of yields as our baseline hypothesis for probing a new state of matter • (This of course one of many possible answers…) }

  22. An Example of Ncoll Scaling • Q: Are there rare probes at RHIC that scale as the number of binary collisions? • A: Yes, charm production (for Ncoll from 71 to 975) PHENIX Run-2 Preliminary Data presented at Quark Matter 2002

  23. Run-2 High pT Results (Peripheral) • PHENIX (Run-2) data on p0 production in peripheral collisions: • Excellent agreement between PHENIX measured p0’s in p-pandPHENIX measured p0’s in Au-Au peripheralcollisions scaled by the number of collisionsover ~ 5 decades • Demonstrates ability (and utility!) of measuring comparison data set in same detector to establish fundamental baselinefor new effects in A-A collisions PHENIX Preliminary

  24. Run-2 High pT Results (Central) Q: Do all processes that should scale with Ncoll do just that? A: No! Central collisions are different . • This is a clear discoveryof new behavior at RHIC • It is presumably a resultdue to formation of unusually denseand opaque matter earlyin the collision • Intense theoretical activity to understand dependence on • Medium properties(?) • Deconfinement(??) PHENIX Preliminary

  25. 2- 4 GeV PHENIX Preliminary 1/Ntrig dN/d  AWAY NEAR AWAY 2- 4 GeV PHENIX Preliminary 1/Ntrig dN/d  More (new) Run-2 results Observation of jet cones (near and away) • Trigger on high pTp0 • Examine angular distribution wrt trigger • Calibrate in p-p by comparison to PYTHIA predictions • Apply to Au-Au • Account for complicationsdue to flow in Au-Au • (In progress) • Systematize yields and shapes as a function of centrality • Relate to suppression

  26. How to Calibrate the Suppression Attempt to separate effects from • Initial state from final state scattering • Cold vs hot nuclear matter via ‘p-A’ (d-Au) collisions B.Z. Kopeliovich et al., hep-ph/0201010 E. Wang and X.N. Wang, hep-ph/0202105

  27. Understanding the Suppression Q. Isn’t the suppression just a measure of the (integrated) density? A. Perhaps, but • That’s what we’d like to determine via measurements in d-Au • As such, it represents a qualitative advance towards understanding effective energy densities R. Baier, PHENIX Collaboration Meeting, Jul-02

  28. PHENIX Preliminary pT dependent systematic error MB trigger 2x2 trigger Expected pT Range in d-Au • C-A D ‘optimistic’ guidance is 4 nb-1 / week • Assume • 50% vertex cut (conservative) • 50% PHENIX efficiency (conservative) • 10 weeks = 10 nb-1 recorded • Scale as 2 x 197  ~ 4 pb-1 p-p equivalent • This is ~ x100 the sample in existing PHENIX p-p result • pT range ‘in excess of’ 15 GeV/c

  29. Yet more (new) Run-2 results First results on J/Y yields Measured in pp via • e+e- (central arms) • m+m- (South Muon arm) s (pp->J/Y) = 3.8 + 0.6 (stat) + 1.3 (sys) mb

  30. Yet more (new) Run-2 results • And J/Y results for Au-Au • Measured via e+e- (central arms) • And binned on centrality • m+m- datastill to come • Clearlystatisticslimited( 24 mb-1 versushoped-for300 mb-1) Phys. Lett B 521 (2002) 195

  31. Charmonium Yields in d-Au • Use measured ‘PHENIX Preliminary’ p-p data as input to color evaporation model: • Reproduces • xF dependence • pT dependence • Total cross section ( 4.0 mb versus quoted 3.8 ± 0.6 ± 1.3 mb ) • Use this parameterization to compute expected yields in for 10 week d-Au run • Results (next slides) PHENIXPreliminary PHENIXPreliminary

  32. J/Y ‘Results’ in d-Au (I) • Broad coverage in xF, pT and x2 by combining • North Arm • Central Arm • South Arm

  33. J/Y ‘Results’ in d-Au (II) • Excellent ability to measure Aa dependence versus various kinematic variables • Again, broad coverage in xF, pT and x2 by combining • North Arm • Central Arm • South Arm

  34. Tagging with “gray” protons • Tremendous utility of event characterization via “gray” protons shown in E910 • Will install refurbished E864 calorimeters inside ring to do same

  35. p↑-p↑ Segment • Assumptions • Duration • 2 weeks set-up • 3 weeks commissioning • 3 weeks data-taking • Performance • 2.8 pb-1 week delivered during data-taking period • 20 cm rms vertex • Polarization > 40% • Longitudinal polarization at PHENIX IP • Physics questions addressed • Measurement of ALL via pion production • Inclusive (comparison) measurements: • J/Y production • Open charm production • High pT hadron and photon production

  36. First Spin Physics (Run-2) • New components • Level-1 triggers • EmCal • Muon • Spin-sorted scalers (4 x 120) • Luminosity with polarization ~ 25%  only very modest effective luminosity

  37. Projected Statistical Error from Run-2 AN Measurement • Even with this very modest start • ~ x 10 previous best (E704) measurement • High pT at x=0 permits pQCD treatment • Should lead to bounds on the product (transversity quark distributions) x (Collins-Heppelman fragmentation function)

  38. Assumed Spin Developments • Spin run is predicated on polarization in AGS ≥ 40% • To be demonstrated during d-Au run • (Soft limit) • RHIC • Achieve <L> ~ 1031 cm-2 s-1 • Commission rotators • Achieve down-ramp • PHENIX • Track spin-dependent (bunch-by-bunch) luminosity • Extend triggers to accommodate x10 increase in luminosity • Commission local polarimeter

  39. Projected Run-3 ALL Measurement • Comparison of projected PHENIX ALL measurements (200 GeV, 3pb-1) with asymmetries predicted for two different assumed gluon polarizations: No detector changes required. Luminosity requirements are consistent with C-A D projections for luminosity. Theoretical interpretation possible in pQCD as demonstrated by comparison between measured PHENIX π0 cross section and NLO pQCD. (next slide) Competes with ongoing efforts at CERN(next slide). W. Vogelsang

  40. 2μ (factorization scale) μ μ/2 Statistical errors only RHIC Reduces Scale Dependence • Already encountered this as part of our p-p comparison data • Now note the direct relevance of this to understanding spin measurements at RHIC PHENIXPreliminary

  41. PHENIX Beam Requirements* for Spin Measurements Physics Goal Center of Mass Energy Polarization Luminosity Gluon polarization -Inclusive hadron production 200 GeV 40% 3 pb-1 -high x prompt photon production 200 GeV 50% 320 pb-1 -low x prompt photon production 500 GeV 70% 800 pb-1 Quark polarization (W-production) same run Transverse spin physics -Collins Heppelman FF 200 GeV 50% 30 pb-1 -Interference FF 200 GeV 70% 300 pb-1 Scheduling priorities: a) Follow RHIC luminosity and polarization profile b) Competing programs at CERN and DESY. (COMPASS has started production running in July 2002!) • Note the requirement for ~103 (~104) improvement in P2L (P4L)

  42. DIS+PHENIX AAC Preliminary Impact of full PHENIX DG Measurement in Direct Photon Production • If the projected PHENIX Prompt Photon Data (200GeV, 320pb-1) are added to a global QCD analysis of existing DIS data: Present DIS AAC Preliminary M. Hirai, H.Kobayashi, M. Miyama et al. (The Asymmetry Analysis Collaboration)

  43. Looking Ahead Run-4: We must measure J/Y in Au-Au ! (Run-3 d-Au request predicatedon commitment to such a runin Run-4) Run-5: • Fully operational muon arm+ new triggers • Full exploration of J/Y productionversus “Nbinary” ~ A(b)*A(b) via • Run-4 long run with Au-Au • Run-5 light ion runs • Spin Continued running to accumulate320 pb-1 at 200 GeV Log10(Nbinary)

  44. Run-2 Goals (previous PAC) • Detector: Commissioning of • New sub-systems • Integration of same into the detector • Calibration of detector • Trigger studies • Experiment: “Complete” what we started in Run-1 • Characterize properties of matter created in highest energy Au-Au collisions on all time scales • ~ “All” pT scales (as permitted by luminosity) • Begin program of J/Y measurements • (TBD) Obtain comparison data for same in p-p collisions • (TBD) Begin spin program. • Every expectation of a repeat performance for Run-3

  45. Re Npart scaling • PHENIX has carefully studied both Ncoll and Npart scaling as a function of pT • Clearly Npart is not the relevant scaling variable • Reference: nucl-ex/0207009

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