Summary of North American Calorimeter R&D Efforts

1. Summary of North American Calorimeter R&D Efforts Sept. 3, 2004 ECFA Workshop, Durham Jae Yu* University of Texas at Arlington • Introduction – Some calorimeter R&D Issues • Particle Flow Algorithm Development • ECAL • Si/W • Scintillator/W • HCAL • Scintillator/Steel • RPC/Steel • Summary *On behalf of all N.A. Calorimeter Groups ALCPG Calorimetry Status J. Yu

2. Some Calorimeter R&D Issues Simulations • Evaluate EFlow • Full simulation [ Gismo→Geant4 ] • Pattern recognition algorithms [ emerging…] , merge with tracks, etc → Full reconstruction [ JAS, Root ] • Optimize detector configuration • Case for jet physics • Low-rate processes (eg Zhh, tth) • Beam constraints vs not • reduce combinations for mult-jet recon. (eg tt→6 jets) • How to combine with other info. (eg flavors from vxd) • e, photon id; muon id; forward (2-photon), missing E • Timing requirement (viz. 2-photon, beam bkgds.) • Opportunities: algorithm development, validity of Geant4, parameterizations, detector ideas ALCPG Calorimetry Status J. Yu

3. EM Calorimeter R&D Issues • Si/W • Cost, readout config., packaging, cooling • Mechanical structure • Optimize sampling vs Si area • Alternatives! [issues] • Scint. tiles [segmentation, light output, readout] • With Si layer(s) ? • Shashlik [segmentation] • Crystals [segmentation, physics case for reso.? ] • LAr Opportunities: generic detector development; detector and electronics prototyping; comparative and detailed simulations ALCPG Calorimetry Status J. Yu

4. HAD Calorimeter R&D Issues • Required segmentation for EFlow? • “Digital’’ detector [issues] • RPCs [reliability, glass?, streamer/avalanche] • Scint. [segmentation, light, readout] • GEMs [scalability, long term reliability] • Other options • Scint. tiles, ….? • Generic Issues: • In/out –side coil • Compensation (partial?) • Absorber material and depth • Integrate muon id with dedicated muon det. • Opportunities: Wide open: detailed simulations in • conjunction with various detector options; detector prototyping ALCPG Calorimetry Status J. Yu

5. Sept. 2004: Where are we? • Essentially all issues are being/have been addressed… …at “some level”  not necessarily a good level • Development of full particle flow algorithm codes • Goal: Physics signals (jet final states) optimized as a function of basic detector parameters: B, Rtrk, cal. segmentation, etc. • Parts of problem have been attacked incompletely • Not easy! Needs to be recognized as a top R&D priority. • Validation of key, new detector innovations • Validation of the MC codes for simulating hadronic showers which in turn will be used to design the calorimeter (using PFAs). This is fundamental to calorimeter progress. • Prototypes in a test beam • Funding a serious issue to be timely ALCPG Calorimetry Status J. Yu

6. Hadronic final states and PFAs LHC Study: Z→ 2 jets D. Green, Calor2002 • FSR is the biggest effect. • The underlying event is the second largest error (if cone R ~ 0.7). • Calorimeter resolution is a minor effect. σM / M  13% without FSR • At the LC, the situation is reversed: Detection dominates. • Opportunity at the LC to significantly improve measurement of jets. ALCPG Calorimetry Status J. Yu

7. Particle flow and calorimeters(cont’d) Complementarity with LHC: LC should strive to do physics with all final states. • Charged particles in jets more precisely measured in tracker • Jet energy 64% charged (typ.) Separate charged/neutrals in calor.  The “Particle Flow” paradigm • ECAL: dense, highly segmented • HCAL: good pattern recognition H. Videau ALCPG Calorimetry Status J. Yu

8. Traditional Standards Hermeticity Uniformity Compensation Single Particle E measurement Outside “thin” magnet (~1 T) P-Flow Modification Hermeticity Optimize ECAL/HCAL separately Longitudinal Segmentation Particle shower reconstruction Inside “thick” coil (~4 T) Particle-Flow Implications for Calorimetry S. Magill Optimized for best single particle E resolution Optimized for best particle shower separation/reconstruction 3-D shower reconstruction in ECAL/HCAL requires high degree of longitudinal segmentation and transverse granularity ALCPG Calorimetry Status J. Yu

9. calorimetry (cont’d) Reconstructing jets using particle flow algorithms: D. Karlen • So the “confusion” term – correctly assigning energies – will dominate  pattern recognition (+ QCD). • 0.3/Ejet is a reasonable goal with good physics justification. • Inserting resolutions for • charged hadrons (tracker) 64% Ejet • photons (EM cal.) 25% Ejet • neutral hadrons (hadronic cal.) 11% Ejet ALCPG Calorimetry Status J. Yu

10. Shower reconstruction by track extrapolation track shower S. Magill ECAL HCAL • Mip reconstruction : • Extrapolate track through CAL layer-by-layer • Search for “Interaction Layer” • -> Clean region for photons (ECAL) • Shower reconstruction : • Define tubes for shower in ECAL, HCAL after IL • Optimize, iterating tubes in E,HCAL separately (E/p test) IL ALCPG Calorimetry Status J. Yu

11. Track Substitution, Neutral Sum Results G4v6.1 • Jet cones – 0.5 • Neutral contribution to E sum ~3.7 GeV (most) • -> Goal is ~3 GeV (all) Charged Neutral Includes mips + cell energies in conical tubes Further tuning of E/p parameter is still needed ALCPG Calorimetry Status J. Yu

12. It’s not just for jet physics… Brient, Calor2004 • Such a calorimeter will also do very well for: • Photons, including non-pointing • Electrons and muons • Tau id. and polarization • 3rd generation • Yukawa coupling • Separation of tau final states → ,  →→+o ALCPG Calorimetry Status J. Yu

13. Possible LC Calorimeter Themes Current paradigms • ECal: Silicon/tungsten • HCal: • “Analog” (5-10 cm seg.) • CALICE tile-cal (TESLA) • “Digital” (1 cm seg.) • SiD: RPCs, GEMs • CALICE: RPCs, GEMs Alternatives • ECal: • Si/scint/W hybrids • Scint/W • Scint/Pb • HCal: • Scint/Pb → Large/Huge Detectors ALCPG Calorimetry Status J. Yu

14. What’s New: Silicon/W, SLAC-Oregon-BNL ALCPG Calorimetry Status J. Yu

15. Dynamically switched Cf • Much reduced power • Much better S/N • Allows for good timing measurement what’s new Si/W (SOB), cont’d ALCPG Calorimetry Status J. Yu

16. Timing with Si/W ECal 50 ns time constant and 30-sample average  ns resolution • Concerns & Issues: • Needs testing with real electronics and detectors • verification in test beam • synchronization of clocks (1 part in 20) • physics crosstalk • For now, assume pileup window is ~5 ns (3 bx) D. Strom Concern reduced now! ALCPG Calorimetry Status J. Yu

17. What’s New: Scintillator/W ECal, Colorado (cont’d) U. Nauenberg ALCPG Calorimetry Status J. Yu

18. Digital HCal with Scintillator (NIU) Density based PFA g recon inside jets Needs validation in test beam ALCPG Calorimetry Status J. Yu

19. Stack & Tile Fabrication ~15pe/mip ALCPG Calorimetry Status J. Yu

20. Tile-Fiber-Reflector Optimization No ageing ALCPG Calorimetry Status J. Yu

21. Relative LY cast extruded ALCPG Calorimetry Status J. Yu

22. Reflector Performance ALCPG Calorimetry Status J. Yu

23. Scintillator/Steel HCAL Status • Simulations and prototyping studies indicate approach competitive with other options. • Detailed R&D studies on tile-fiber-reflector optimization, photo-detector characterization, efficient assembly have been successfully completed. • Focus shifting to test beam prototype ALCPG Calorimetry Status J. Yu

24. What’s New: DHCal with RPCs, ANL (On-board amplifiers) Pad array Mylar sheet Resistive paint • AIR4 is a 1-gap RPC built with 1.1mm glass sheet • 1.2mm gap size • Resistive paint layer is about 1MΩ/□ • Running at 6.8 KV • Avalanche signal ~5pc • Efficiency >97% • Total RPC rate from 64 channels <10 Hz • Very low noise! 1.1mm Glass sheet 1.2mm gas gap GND 1.1mm Glass sheet Resistive paint -HV Mylar sheet Aluminum foil ALCPG Calorimetry Status J. Yu

25. ANL RPC R&D Plan FY 2004 • R&D with chambers • Essentially completed • Electronic readout system • Design and prototype ASIC • Specify entire readout system • Prototype subcomponents • Construction of m3 Prototype Section • Build chambers • Fabricate electronics • Tests in particle beam • Without and with ECAL in front CY2004 and early 2005 CY2005 CY2006 - 8 ALCPG Calorimetry Status J. Yu

26. Calorimeter R&D Summary ALCPG Calorimetry Status J. Yu

27. J. Repond Validate various technical approaches (technique and physics) Many novel concepts: Fine granularity E/HCAL, DHCAL, Calorimeters with RPCs/GEMs, SiPMs… Validate various concepts of the electronic readout Many novel concepts: Imbedded ECAL readout, cheap digital readout… Measure hadronic showers with unprecedented spatial resolution Validate MC simulation of hadronic showers Compare performance of Analog and Digital HCAL Prerequisite for designing the LCDs Comparison of hadron shower simulation codes by G Mavromanolakis ALCPG Calorimetry Status J. Yu

28. The Test Beam Prototypes • Particle Flow will be tested and detectors optimized using full Monte Carlo simulations • These Monte Carlos (ie Geant4) must be validated with test beam • A new regime: “Imaging” hadron (and em) calorimeters • Previous MC-cal comparisons not especially relevant • Hadron showers are spatially large  a large prototype is needed (with an ECal in front) • 1 m3 , 4105 readout channels • This requires funds (more than current LCRD/UCLC awards) • Meanwhile, initial R&D goals are at or near completion ALCPG Calorimetry Status J. Yu

29. Summary • Significant progress made in N.A. Calorimeter R&D • Based on preliminary Particle Flow results and educated guesses, the critical detector R&D has gone very well. • We have learned much about LC requirements • eg timing and hermeticity requirements (The ITRP process) • Further progress on PFAs is critical for detector optimization • Test beam validation of simulations is crucial for the cal. effort. • This can go on in parallel with the PFA developments • Strong funding support is needed for the quantum jump to the next step • Plan to participate in the world-wide effort for a coherent Test Beam program ALCPG Calorimetry Status J. Yu