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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/rbupsep01/PACSep01.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 ( this talk available at http://www.phenix.bnl.gov/phenix/WWW/publish/zajc/sp/presentations/rbupsep01/PACSep01.htm )
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” current run
In Pictures For 2001 Run:
PHENIX Central East Carriage Ring Imaging Cerenkov Drift Chamber Beam-Beam Counter Central Magnet West Carriage
Trigger Counters • The mapping of correlated (ZDC,BBC) signal into ‘Nparticipants’ essential to nearlyall PHENIX Run-1 physics results • Better performance in Run-2 due to improvedunderstanding of electronicsand thresholds
Multiplicity and Vertex Counter (MVD) • Run-1: Engineering Run • Run-2: ~50% of detector instrumented
Drift Chamber • East DC rebuilt during Run-1/Run-2shutdown • Improved gas, operating voltages • Run-2 performance • Improved single-wire efficiencies (85% to 97%) • Improved resolutionnow 120 to 140 mm(design value 150 mm)
Pad Chambers • Run-1: • PC1,3 in East Arm • PC1 in West Arm • Run 2: • Added PC2,3 in West Arm(in situ!) • Good correlationbetween z-vertex from • BBC (timing) and various • PCi,j,(k) combinations
RICH • A vital component in ourelectron identification • Higher integrated luminosityavailable in Run-2 • Much greater reach in hadron pT • Will use RICH to also identify pions for pT > 6 GeV/c
Time-of-Flight Run-1 • An essential component in our high quality identified particle spectra Run-2 System is calibrated and performing well in Run-2
Time Expansion Chamber • Run-1: 4 sectors installed(2 instrumented) • Run-2: all 4 sectors instrumented
EmCal • Completed aperture significant increase in coverage (~3 sectors to 8 sectors) • All sectors calibrated and operational ~600K (vertex restricted) BBC triggers
All Together Now Displayed: • BBC • DC • PC • TEC • TOF • EMC • Tracking
Muon Identifier • First detector system installed at RHIC First detector system damaged at RHIC Operation deferred to Run-2 Robustness now established
Muon Tracking System Muon Event Station 1 Radiograph Station 2 Residuals First dimuon spectrum--no cuts
Run-2 DAQ and Trigger PHENIX has made a major effort to • Design and build a system capable of extracting all physics at design luminosity • Have it ready for Run-2
Run-2 DAQ and Trigger • High bandwidth + physics triggers • Able to use full luminosity of machine • To date: • Implemented full set of Level-2 triggers • Single muon • J/Ym+m- • J/Y e+e- • f e+e- peripheral (40-100%) • High pT • Photon (2.5-3.0 GeV/c cut) • Electron (2.5 GeV/c cut) • Charged (cut TBD) • e-m coincidence • Coherent peripheral trigger • DAQ Upgraded to • ~30 Mb/s recording • ~150 events/sec
Physics from Requested Segments • Au-Au: • 3M F K+K- decays • 30K J/Y m+m- in South Arm • 6K J/Y e+e- in Central Arms • 15K (charm) e’s with pT > 2 GeV/c (central 10%) • ~ 20 p0’s / GeV at pT = 25 GeV/c • p-p comparison data: • Measurement of same probes as in Au-Au with roughly half the statistical precision • Polarized-p on Polarized-p: • An essential start on understanding systematics in these measurements • A first look at DG
Run Segments • Assumptions: • A total period of 25 weeks for beam availability • RHIC duty factor = 50% • PHENIX duty factor = 50% • Collision region rms = 20 cm. • All running at • Au-Au segment of 17 weeks: • First 7 weeks: • RHIC: commissioning from ~10% to 100% of design luminosity • PHENIX: Commissioning, calibrating, start of data-taking • Last 10 weeks: • Running at ~100% of design luminosity (2 x 1026 cm-2 s-1) • 300 mb-1 of integrated luminosity recorded • p-p segment of 8 weeks • 2 weeks to commission collisions • 1 week to commission polarization (> ~50%) • 5 weeks of polarized running at 5 x 1030 cm-2 s-1 • 3.5 pb-1 of integrated luminosity recorded:
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.
To Date • Commissioned all installed detectors • Implemented Level-2 algorithms • Begun Level-2 physics studies • Begun minimum bias physics program • ~10M events recorded • ~ 3x Run-1 data set (with much upgraded detector) • ~60% of delivered luminosity • < 1% of our desired recorded event sample • Run-2 rare physics requires significant improvement in luminosity
Delivered Beam to Date • Average over last two weeks • ~20M ZDC counts/wk 2 mb-1 /wk • Design x 50% availability = 60 mb-1 /wk • This must change significantlyto access high pT, J/Y, etc. Run-2 Run-1
Priorities for Remainder of Run Our highest priority: • Development of higher luminosityvia improvements in • Number of bunches (56 112) • Storage RF (better capture, lifetimes) • b* (5 m 2 m) • Increase integrated luminosity via • More stable operation • Shorter stores with higher average L(may require revision of voting system)
Proposed Use of Extended Time 1.) Sufficient additional running of • Au-Au at sNN = 200 GeV and/or • (polarized) p-p at s = 200 GeV to achieve our stated goals for Run-2 2.) A d-Au run at sNN = 200 GeV 3.) Anything else
Why d-Au (1) • It provides a “p-Au” run with minimal machine complications: • Equal-velocity counter-rotating bunches a “solved problem” • But this implies different rigidities, e.g., at 100 GeV • 100.4647 (proton) • 200.9293 (deuteron) • 250.5258 (Au) • “Insertion angle” through DX magnet • ~4 mr (p-Au) 6.5 cm at ZDC (bad) • ~1 mr (d-Au) 1.5 cm at ZDC (acceptable) • Source: • Recent tests and developments by Tandem staff very encouraging ~ equivalent per nucleon luminosities for (p-p, Au-Au, d-Au) • Fault studies performed, also encouraging(to be reviewed by BNL safety committee 15-Oct-01)
Why d-Au (2) • General: Historically, p-A data has been essential in separating “mere” multi-particle effects from “genuine” heavy ion effects • Strangeness enhancement (e.g. E910, NA49) • Gluon shadowing (e.g. FNAL E866) • Specific: The truly new result from Run-1 isthe suppression of high pT hadrons • A “proton”-nucleus data set will provide the key information to distinguish between effects in cold nuclear matter versus hot (deconfined) nuclear matter
Looking Ahead Run-3: (Subject to the usual caveats about surprises and flexibility): • Heavy Ions • Fully operational muon arm+ new triggers • Full exploration of J/Y productionversus “Nbinary” ~ A(b)*A(b) via • A long run with Au-Au • A series of shorter light ion runs • p-A or d-A running • Spin Continued running to accumulate160 pb-1 at 200 GeV Log10(Nbinary)
pp Energy Scans? • Existing • HBT • V2 • Multiplicity data show smooth, monotonic variation from AGS to SPS to RHIC
From Previous PAC • Available FY01 inadequate for additional commissioning and programmatic needs of RHIC. • Colliders require extended running to • Maximize luminosity • Develop stable operations(Cf. Tevatron, HERA) • Short runs maximize end effects (very non-trivial at a cryogenic machine) • RHIC in Run-2 is a new machine • we must “pay” the commissioning “bill” • “Solutions” that avoid p-p running delay by 1 year or more quantitative baseline comparisons • “Solutions” that do not include spin running • Delay measurement of DG by at least one year • Put at risk BNL’s primacy in this measurement • Ignore international contributions to the spin program • All of these factors argue for combining the FY01 and FY02 run periods • N.B. 1 nominal RHIC run per 2 fiscal years is not a long term solution!
RHIC Spin Collaboration • RHIC Spin plan: http://spin.riken.bnl.gov/~saito/LRP/BNL-final.ps • A stable, mature set of goals • Based on 10 weeks/FY of dedicated spin running • Extends over 6 years (first 3 shown below) • Run-2 • 200 GeV, L dt = 7 pb-1, 1 snake, P=50% Commissioning, first measurement of gluon polarization with pions • Run-3 • 200 GeV, L dt = 160 pb-1, Snakes + rotators, P=70% Gluon polarization with direct photons, heavy flavor • 500 GeV, L dt = 90 pb-1 Commissioning, u-quark polarization • Run-4 • 200 GeV, L dt = 160 pb-1, Snakes + rotators, P=70% Gluon polarization with direct photons, heavy flavor • 500 GeV, L dt = 120 pb-1 Sea-quark polarization, parity violating W-production, new physics
Completion • Complete the central arms ( 2001) • 4 additional sectors of EMCal readout • 2 additional sectors of TEC readout • Install Pad Chambers 2 and 3 in West Arm • Prepare for muon physics ( 2001) • Install South Muon Magnet with 3 stations of tracking • Instrument South Muon Identifier panels • Complete vertex detector (2001-2) • Commission ( 2001-2) • Appropriate triggers • Additional DAQ bandwidth(NB: All detectors and front ends allow running at x10 Au-Au design luminosity) • Complete North Muon Arm (2002-3)
Shutdown • Planning well underway for entire list of upgrades during Run-2/Run-3shutdown • Any extended running must be complemented by delayed start to permit this
Summary • A massively upgraded PHENIX detector is operating in Run-2 • Delivered luminosity to date a very small fraction of our Run-2 goal • Priorities 0.) Significant improvements in luminosity 1.) Au-Au, p-p running to fulfill our Run-2 goals 2.) d-Au running provided • significant extended running become available • #0 and #1 are satisfied
Possible Run Plan (Largely for ions; significant spin running each year is assumed) • Run-2: • Au+Au, first p-p , d-Au comparison runs • First look at J/Y production, high pT • Run-3: • High luminosity Au+Au (60%) of HI time • High luminosity light ions (40%) of HI time • Detailed examination of A*B scaling of J/Y yield • Run-4: • p-d/p-p comparisons • Baseline data for rare processes • Run-5: • “Complete” p-A program with p-Au • Energy scans • Systematic mapping of parameter space