1. Energy Flow Studies Steve Kuhlmann Argonne National Laboratory for Steve Magill, Brian Musgrave, Norman Graf, U.S. LC Calorimeter Group

2. Introduction/Outline Detector is described in Dhiman’s (1st) talk (Si-W EM Cal, 5 mm X 5mm, R=127 cm, 17%/  E) Software is the same as Dhiman’s (2nd) talk Conversion to Geant4 soon Real Track Pattern Recognition Included Will Discuss: General Energy Flow Issues Track Depositions in EM Calorimeter and Simple Photon Finder

3. Physics Motivation I: Higgs Self-Coupling with no beam constraint Physics Motivation II: Electroweak symmetry breaking without an elementary Higgs (also no beam constraint) Question: Any More?

4. Question from Jeju and Calor2000: Will Hadronization or Jet Clustering Ruin Resolutions? No, at least if backgrounds are small

5. Particle Content of Hadronic Z Decays at  s = 91 GeV

6. Particle Energies in Hadronic Z Decays at  s = 91 GeV Charged, Mean E=2.85 Photons, Mean E=1.0 Neutrons/K0L, Mean E=4.35

7. Resolution components of Hadronic Z Decays at  s = 91 GeV Assuming Perfect Identification in this Detector Configuration Neutrons+Klong 2.9 GeV Photons 1.4 GeV Tracks 0.25 GeV Put together in Tesla TDR in Energy Flow algorithm

8. Effect of Neutrinos in Hadronic Z Decays

9. Tracking cannot be assumed to be perfect, forward tracking and “curlers” are issues Effect of ignoring charged particles below certain thresholds Tesla TDR, is fine if achieved

10. Track Reconstruction Efficient Down to Pt=0.5 GeV in Barrel Region

11. Single 10 GeV  -

12. Effect of possible Photon or Neutron/K0Long thresholds Sum of all energy except photons < 0.2 GeV Sum of all energy except neutrons/K0L < 0.5 GeV

13. Determining Charged Particle Depositions Energy deposited in last EM layer (within 0.6 0 of track) Easy to recognize MIP Easy to recognize MIP Easy to determine 1 st layer of pion shower Easy to determine 1 st layer of pion shower Interactions Single 2 GeV  - Single 2 GeV Muon Tail OverflowsZeros

14. Determining Charged Particle Depositions Single 2 GeV  - Next step in “Track-seeded” Energy Flow is to remove all hits in each layer based on something like red histogram, then cluster photons and neutrons/K0L. Energy weighted

15. Hadronic Z Decay

16. Hadronic Z Decays at  s = 91 GeV Simple photon finder: Remove EM Clusters within 0.03 of Track, unless track was MIP in all 30 layers. Then remove if within 0.01.

17. Single 10 GeV  -

18. Separate photons from neutrons/K0L with 3-layer shower max energy > 30 MeV 2 GeV Electron 2 GeV  - ddd MeV

19. Hadronic Z Decays at  s = 91 GeV

20. Width=3 GeV, Goal is 1.4 GeV Hadronic Z Decays at  s = 91 GeV

21. Questions for the Future Other Physics Analyses that Need 30%/  E Jet Resolution? How much better is a large detector? Digital or Analog Hadron Calorimeter? Optimized segmentation for physics/costs?

22. Determining Charged Particle Depositions Single  - Next step in “Track-seeded” Energy Flow is to remove all hits in each layer based on something like red histogram, then cluster photons and neutrons/K0L. Energy weighted

23. Determining Charged Particle Depositions Interaction Layer 0 Abs(Delta-Theta) Interaction Layer 26 Abs(Delta-Theta) Interaction Layer 17 Abs(Delta-Theta) Interaction Layer 8 Abs(Delta-Theta)

24. Determining Charged Particle Depositions