Calorimetry Upgrades at Forward Rapidities for the PHENIX detector

1. Calorimetry Upgrades at Forward Rapidities for the PHENIX detector Mickey Chiu University of Illinois at Urbana-Champaign

2. Approach: internal expertise + new expert groups N C C INFN Trieste, Italy UC Riverside, US Brookhaven Lab, US Iowa State, US Moscow State, Russia JINR Dubna, Russia Moscow Engineering, Russia Ewha U, Korea Yonsei, Korea Charles U, Czech. Czech Tech, Czech Czech IOP, Czech M P C Kurchatove Institute, Russia Hiroshima Univ, Japan Oak Ridge Lab, US Brookhaven Lab, US UIUC, US Stony Brook, US Univ. of Colorado, Boulder, US RIKEN, Japan

3. PHENIX Detector Nose-Cone Calorimeter (NCC) Muon Piston Calorimeter (MPC) Baseline (Complete in 2003) • Central Arm Tracking || < 0.35 • Drift Chambers (DC) • Pad Chambers (PC) • Time Expansion Chamber • Central Arm Calorimetry || < 0.35 • PbGl and PbSc • Very Fine Granularity • Tower x ~ 0.01x0.01 • Central Arm Particle Id || < 0.35 • RICH • electron/hadron separation • TOF (East Only) • /K/p identification • Global Detectors (Luminosity,Trigger) • BBC 3.0 < || < 3.9 • Quartz Cherenkov Radiators • ZDC/SMD 0 • Forward Hadron Calorimeter • Muon Spectrometer Arms 1.2 < || < 2.4 • Muon Tracker • Muon Identifiers As a complete, mature experiment, PHENIX’s excellent capabilities in leptons, photons, and hadrons make improvements more challenging

4. Barrel Si MPC NCC FWD Si NCC FWD Si MPC PHENIX Acceptance Central Arms ZDC FCAL FCAL ZDC Muon Muon Over 10 times increase in rapidity acceptance for 0, , and “jets”. Large acceptance for g-jet tomography: Expect measurements out to Ejet > 20 GeV Large acceptance for flavor tagging Limited acceptance for p – meson separation

5. NCC, MPC Coverage NCC, MPC Physics with NCC and MPC • Heavy Ions (A+A) • energy loss • +jet: controlled measurement of energy loss • 0, jet suppression • further constraint on L dep by y variation • improved reaction plane resolution • Cstates: screening, deconfinement • p+A (or d+A) • Gluon Saturation Effects? • higher rapidity  lower x • 0, jet, direct  • Initial conditions in A+A • Longitudinally polarized p+p • +jet: golden channel for g measurement • dominated by gluon compton • event by event x-dependence of g • Transversely polarized p+p • forward asymmetry of 0, jet,  • decoupling of effects • Sivers, Collins, transversity, higher twist GS95 prompt photon central arms

6. The Nosecone Calorimeter Upgrade • tungsten silicon calorimeter • two EMC compartments 1.5x1.5cm2 pads, separated by π0/γ identifier with 0.5x0.5mm2 pads and 2.5mm • thick tungsten plates: Lrad=10 • one hadronic compartment with same pad size but the tungsten is 16mm thick. • reasonable resolution • g&e identification • g – p0 separation • isolation (electrons and muons) • jet finding and coarse jet measurements • e/g/jet triggers Challenging technical requirements, but devices with similar specifications have been built for e.g. balloon based experiments

7. NCC Specifications Data in the table are for a single calorimeter

8. Geant Studies of performance 30 GeV/c 0 in NCC towers strips

9. bkg (simulated) h=1-1.5 bkg (extrapolated) dir photon pt NCC in central Au+Au Problem is pile up faking a photon Problem worst at high h since the effective segmentation is larger • y=1-2 looks pretty good, above 2 under study.

10. Proof-of-principal prototype Silicon Pads Readout Board

11. MPC Mechanical Design and Issues Preliminary Layout • RHIC Beam-Pipe • Flange & Bellows • Muon Tracker Air manifolds • 220 cm from vertex, 2.2x2.2 cm2 crystals • Angular Resolution:  = 0.010.01

12. Crystals and APD Readout North Crystals PWO (Apatity, Russian) APD Holder PWO Crystal PreAmp • PHENIX fortunate to have collaborators also on PHOS (ALICE) • Use existing crystals (from Kurchatov), APDs, preamps (from Hiroshima) • Need transition card to PHENIX DAQ • Need HV Control • Need Mechanical Support Structures • Leverage existing expertise – significantly reduces development time

13. MPC Simulations Geant Study of a very hard PYTHIA events 27 GeV anti-neutron 11 GeV 0 photon pair • Clear separation of 11 GeV pi0 photons • Poor response to anti-neutrons (and all hadrons) • work underway to optimize pattern recognition using transverse shower shape

14. PHENIX Upgrade Schedule Scenario R&D Phase Construction Phase Ready for Data

15. Summary • RHIC and it’s detectors, including PHENIX, are complete and have produced exciting early results in heavy ion physics • PHENIX designed as a high-rate, high-granularity, small-acceptance detector optimized for photons at mid-rapidity and leptons • Most of the real estate is taken up • However, there is still a lot of potential for clever calorimetry upgrades which squeeze in to the remaining space in PHENIX • The detectors are small but have big physics potential • Better than an order of magnitude increase in acceptance for 0, direct , jets • More than just statistics – fundamentally new physics capabilities from increased kinematic coverage • In the case of the NCC, this can be done surprisingly economically • despite the high cost materials, small size limits total cost • NCC R&D well on its way: simulations, hardware prototyping, procurement. • For the MPC, leveraging existing expertise and hardware allows us to fund the detector construction almost entirely from university resources • Possibility of MPC engineering run during Run06. Otherwise, will work towards Run07.

16. Backup Slides

17. South Magnet Temperatures Cooling Water Temp Air Temp