1. Muon Spectrometer Upgrade, July 14 th Muon Spectrometer Upgrade Matthias Grosse Perdekamp, RBRC and UIUC Physics Motivation Components of the upgrade People and Schedule o W-physics: Increase the rejection of the single muon trigger to 10 4 (design: 10 3, observed: 10 2 ). o Gluon saturation at small x in d-Au: Extension of the kinematic range for direct photon production to small x. o  first level trigger for Heavy Ion Physics o Increase stability of muon trigger against beam related backgrounds. Front electronics and trigger

2. Muon Spectrometer Upgrade, July 14 th Physics Motivation W Production in pp Gluon Saturation in dA  Level 1 trigger in AA Study color screening effects associated with QGP production in  quarkonium states: The seperation of the  (1S) state from the  (2S) and  (3S) states requires good invariant mass resolution (100MeV) and requires long runs at as high as possible integrated luminosity. Measure the A-dependence of the gluon distribution at small x: o Survey the dependence of nucleon structure on the nuclear environment. o Search for gluon saturation at small x: 10-3<x<10-2 o Survey initial state for HI high pT physics.

3. Muon Spectrometer Upgrade, July 14 th Level 1 Channel Rates electron trigger 4kHz (EMCxRICH, E>1.5GeV) R=3000 photon trigger (EMC>3GeV) 0.3kHz R=40000 Jet (EMC Multiplicity) 6kHz single muon 17.6kHz (muId deep muon) R=570 Others 2kHz Total 29.9kHz PHENIX bandwidth 12kHz (->24kHz for $2M) Projected Rates in pp: o rate from level 1 should stay below about 7-8kHz o can pre-scale electron trigger and jet trigger by factors 2-3 (as event samples are going to be several 10 6 events). o W sample is about 10 4. o Maschine Luminosity will increase over several years (first 500 GeV production run: Time scale to fix the trigger problem is 3-5 years. o Ken Reed et.al and Jamie Nagle et al. found “default R(uId)” of about 1000. o We do not have a reliable estimate of beam related background in the muon trigger. o need additional rejection of 10-50 depending on the beam background trigger rate.

4. Muon Spectrometer Upgrade, July 14 th p muon Muons from Ws Nosecone Calorimeter Hodoscope I Pad Chamber I Cerenkov Muon from hadron decays Jet vs W Muon from W Muons from hadrons Nosecone calorimeter -> dA: low x, pp: W-tag, b-tag Pad Chambers+uID -> high momentum lepton and di-lepton trigger for pp, AA hodoscopes+uID -> pp: W-tag Cerenkov+uID -> AA:  trigger, beam gas rejection pp: W-tag Hodoscope II Upgrade Components: Pad Chamber II

5. Muon Spectrometer Upgrade, July 14 th Pad Chamber: 360 azimuthal strips made as an digital.OR. of individual pads Amp/Disc.OR. 2 mm pitch proportional wire chamber for gain amplification Cathode plane

6. Muon Spectrometer Upgrade, July 14 th Level 1 Tracking: Hodoscope + muID RoadLevel 1 Threshold: Cerenkov + muID Road raw decay muons with muID lvl1 with tracking with Cerenkov Pythia and PISA simulation by Greg ver Steeg and Jennifer Hom Rejection: 3.7 Rejection: 36 Example: Single Muon Trigger Rejection

7. Muon Spectrometer Upgrade, July 14 th Example: N-EMC, kinematic coverage Pythia simulation by Rich Seto More than 100 events in bin width  logx=0.1 More than 10 3 events in bin width  logx=0.1 More than 10 4 events in bin width  logx=0.1 More than 10 5 events in bin width  logx=0.1

8. Muon Spectrometer Upgrade, July 14 th Channel Counts for one Muon Arm Pulse Height Timing Pattern

9. Muon Spectrometer Upgrade, July 14 th Plans: (1) Time Schedule : a) first 500 GeV run in 2005: (low luminosity) b) max. Luminosity in 2006 or 2007 (2) Menu of possible upgrades: a) new LL1/L1.5 electronics b) two tracking hodoscopes c) two pad chambers d) segmented nosecone calorimeter e) Cherenkov (3) Interested groups: o RBRC (Brendan, Abhay) o Kyoto (Naohito) o RIKEN (Atsushi) o Columbia (Chi) o UCR (Ken, Rich, Wei) o UIUC ( JCP, MGP) o Iowa (John Lajoie) o UNM (Doug) (4) Funding: a) RIKEN/RBRC b) Kyoto (requested R&D funding) c) UIUC ($200k) d) NSF MRI grant: Consortium of UIUC and UCR University : December NSF : December/January