24-May-99W.A. Zajc Goals l Detector: Commissioning of q All active sub-systems q Integration of same into a detector q Calibration of detector q Acquisition of large, minimally biased data set for trigger studies l Experiment: q Characterize properties of matter created in highest energy Au-Au collisions on all time scales (  “All” p T scales) q Obtain comparison data for same in p-p collisions q Maintain progress towards a spin run in Year-2

24-May-99W.A. Zajc Request (summary) (In priority order) 1. Sufficient Au-Au running to q Commission and calibrate Year-1 detector  Record 20  b -1 of Au-Au collisions at 2. Spin commissioning of one ring 3. A p-p comparison run at 4. Anything else General desiderata: q Early development of stable running conditions q Steady luminosity growth q Flexibility in scheduling of accesses and/or shutdowns

24-May-99W.A. Zajc Request (History) l 96-97: Extensive studies by “Day-1 Task Force” q Chair: B. Jacak q Determination of PHENIX goals for Year-1 q Consultation with machine experts l May-98: Strong endorsement of spin commissioning q (Letter from WAZ on behalf of PHENIX to Drs. Kirk and Ozaki.) l May-99: PHENIX Executive Council endorses extending spin commissioning studies to include p-p comparison run.

24-May-99W.A. Zajc East vs. West l East has superior q hadron capabilities q electron capabilities q high p T capabilities è Give highest priority to East Arm construction q West Arm to be completed as time, funds and schedule allows q Accept schedule risk with East Arm completion l This is the basis of our current plan with RHIC management and our Year-1 physics program

24-May-99W.A. Zajc Status- Now Presently: ER = “Engineering Run” q Sub-systems: u Zero-Degree Calorimeter (full) u Beam-Beam (full) u Drift Chamber: (prototype ~ 3/20 of sector) u Pad Chamber: (PC1 prototype) u RICH (portion of West Arm) u EmCal: (2/18 of one PbSc sector) u Time of Flight: (1 of 10 panels) u Time Expansion Chamber (2 half-planes of one sector) u Trigger, timing, DAQ (~full chain) q Goals: u Understand sub-systems u Perform system test u See initial collisions

24-May-99W.A. Zajc Year-1 Status After roll-in of East Arm: q Global: u MVD u BB u ZDC q East Arm u All sub-systems mounted u 50% (at least) read out q West Arm u Minimally: ER configuration u Optimally: m DC installed ~15-Sep m PC1’s “ “ “ m + other instrumentation as available.

24-May-99W.A. Zajc PHENIX Assumptions l Data Acquisition capable of recording all Au-Au events up to 10% of design luminosity l East Arm availability to take advantage of entire “useful” period of Au-Au running

24-May-99W.A. Zajc

24-May-99W.A. Zajc Start of East Arm Work

24-May-99W.A. Zajc RHIC Assumptions l Total RHIC running period: 30 weeks l Total time devoted to Au-Au running: 20 weeks q Remainder to spin, p-p run, machine development, accesses… q 20 weeks = 8 weeks commissioning + 12 weeks running l Linear increase of luminosity: l Energy for all Au-Au running: l RHIC duty factor: 50% l PHENIX duty factor: 50%

24-May-99 Physics from Au-Au l With these assumptions:  20  b -1 recorded è120M unbiased Au-Au events l Physics reach: q An extensive program addressing all collision timescales q (This list not necessarily complete)

24-May-99W.A. Zajc Global Variables l Large-cross section phenomena q 30 events q 2000 events l Analyses from q Full simulation u Backgrounds u Detector response q Full analysis chain used in MDC2

Photons l Calorimeters (PbSc + PbGl) ideally suited for photon detection in heavy ion environment: q High segmentation q High energy resolution q Good time resolution l Inclusive photon spectrum in 150 events (full simulation)

24-May-99W.A. Zajc Photons (expanded) l This study concentrated on cluster reconstruction and cluster shape cuts l (Large) additional discrimnation via q Time-of-flight q Tracking

24-May-99W.A. Zajc Calorimeter provides superb  0 reconstruction to p T ~ 25 GeV/c l Here studied at p T = 4 GeV in central Au-Au event as a function of asymmetry:  0 ’s

24-May-99W.A. Zajc Hard Scattering l Major new feature of RHIC: hard scattering l 120M events in PHENIX clearly accesses this regime: l Large p T range èAccess to earliest time scales in collision l Unbiased event sample èSystematic study versus impact parameter èAbility to use hard parton propagation as probe of dense nuclear matter

24-May-99W.A. Zajc Charm l Intrinsic interest due to q Large mass scale q Possible thermal enhancements q Suppression in -onium states q Possible large energy loss effects l Mode for initial observations: High p T single electrons (from semi-leptonic decays of D’s) Expected yields for 20  b -1 : q p T > 1 GeV/c: 25K/ (Year-1 arm) q p T > 2 GeV/c: 1K/ (Year-1 arm) l Challenge: q Understand contributions q Understand experimental sensitivity

24-May-99W.A. Zajc Charm Analysis Details l Required components:  e/  rejection > ~10 3 u Combination of RICH, EmCal, TEC èRedundancy allows study of systematics q Understanding of Dalitz backgrounds  Measure  0 and  ’s in situ u Simulations for comparison q Understanding of conversions u Measure with background runs u Simulations for comparison l Results on efficiencies from full simulation: q Track reconstruction: 80-85% q Cerenkov nPMT cut : 95% q Cerenkov ring shape : 91% q EmCal match, E/p : 92% q TEC electron PID : 90%

24-May-99W.A. Zajc   K+K-  K+K-  K+K-  K+K- Vector meson accessible via both hadronic and leptonic decays q Results shown for u 6M Minimum Bias events u In TOF aperture u ~10K in acceptance q Extensions u Factor of 20 more data èStudy versus centrality u Use TOF in EmCal m Factor of 2-4 more solid angle m Improved S/B (over reduced p T range)

24-May-99W.A. Zajc Additional Physics l Program discussed thus far: q Possible with East Arm only q (Plus many other topics) l Possible upgrade of West Arm detectors from their “Engineering Run” configuration q Greatly increases our physics reach q Examples: u Back-to-back high p T pairs Study parton dynamics, dE/dx, “jet-quenching” u Decays of vector mesons to e + e - :

24-May-99W.A. Zajc Importance of Spin Commissioning l Looking ahead: PHENIX will request a 10 week polarized p-p run at 200 GeV in Year-2 This allows for first measurement of  G/G at “high” p T via:  Inclusive  0 ’s  J/  production èA major opportunity for RHIC to make an essential, timely contribution èSpin studies in Year-1 are a necessary pre-cursor to this physics program.

24-May-99W.A. Zajc Arguments for p-p Running l There are no p-p data at l Obvious advantage of in situ measurement of our most important baseline. l Study of p-p dynamics in machine + detector beneficial to timely development of Year-2 spin program.

24-May-99W.A. Zajc MDC2 Results 1) Transferred data from counting house to RCF (not yet over the final fast link, but this was a good proof of principle) 2) Reconstructed (CRS) and analyzed (CAS) (multiple times) q ~100K central Au+Au events q ~600K p+p events. 3) Demonstrated efficient use of CRS for reconstruction data throughput from HPSS: 28-30MB/sec demonstrated 4) Demonstrated reconstruction in new offline (ROOT based)framework. Faster than STAF reconstruction by a factor ~2. 5) Showed that PHENIX reconstruction code fits into RCF resources. q Job size was ~ MB. q Time required was seconds per event. è PHENIX analysis fits into the expected number of CRS machines and that 256 MB is sufficient. 6) demonstrated analysis on CAS q Connect tracking subsystems -> tracks (in reconstruction) efficiency ~85% q Associate PID detectors -> particles (in reconstruction) q Cuts to select particle ID -> electrons, muons, pi0, kaons q Analyzed (in analysis step) reconstruct vector mesons efficiency ~60% q new round of optimization is happening now 7) Demonstrated performance of detector and software detector response matched to beam test info acceptance, efficiencies commensurate with CDR many background levels measured from MDC2 events 8) Collaboration (through PWGs) now using CAS machines. PHENIX gave input to CAS purchase (mainly work of Jeff Mitchell and Dave Morrison) 9) Developed scripts to generate large numbers of simulated events; demonstrated use both at RCF and at CC-J. 10) Developed very useful MDC web site, which guides one through the entire software chain.

24-May-99W.A. Zajc Run Coordination l Run Coordination Task Force q Dec-98: Task force charged with developing plan q Feb-99: Report of Task Force endorsed by Executive Council q Jun-99: Expect same from Institutional Board l Report Available q In the written Beam Use Proposal q announcements/RC.doc.html l Plan provides for q Safe and systematic conduct of PHENIX shifts q Management hierarchy for same q Fair allocation of shifts between institutions

24-May-99W.A. Zajc Summary l Proposed program q Thorough initial study of highest-mass, highest-energy collisions ever made q Minimum bias  maximal ability to understand data set and effect of (later) triggering q Measurement of p-p collisions to characterize baseline physics q Maximal overlap with machine development of u Stable operations u Spin running l Experiment will be ready to implement this program (detector and analysis chain) l Collaboration committed to safe and systematic operation of PHENIX