1. 1 Physics Impact of Detector Performance Tim Barklow SLAC March 18, 2005

2. 2 Outline General Considerations –Vertex Detector –Tracker –Calorimeter –Far forward detector Examples of parametric physics studies –Calorimeter  E jet –Tracker  p t Summary

3. 3 Vertex Detector Classic application of b,c tagging to Higgs branching ratios. But there’s more: –vertex charge top, W helicity asymmetries  tagging stau analyses Higgs tau BR b jets with several ’s *Talk by Chris Damerell 21Mar2005

4. 4 Vertex Detector – tau tagging example

5. 5 Tracker Momentum resolution set by recoil mass analysis of reconstruction and long-lived new particles (GMSB SUSY) Multiple scattering effects Forward tracking Measurement of Ecm, differential luminosity and polarization using physics events Recoil Mass (GeV)

6. 6 Calorimeter Separate hadronically decaying W’s from Z’s in reactions where kinematic fits won’t work: Help solve combinatoric problem in reactions with 4 or more jets  E /E = 0.6/E  E /E = 0.3/E

7. 7 Far Forward Detector Electron veto down to 3.2 mrad in presence of very large pair background Useful in general to suppress backround. Takes on added importance given that the SUSY parameter space consistent with Dark Matter density includes region with nearly degenerate Crossing angle implications.

8. 8  M/M stau (%) Far Forward Detector Rel. stau mass error increases from 0.14% to 0.22% with 20 mrad cross angle

9. 9

10. 10 Reconstructed M bb 4C Fitted M bb M bb (GeV)

11. 11 M bb (GeV)

12. 12

13. 13 Simdet Fast MC with this parameterization of pt resolution in place of Simdet’s emulation of LDC: SiD Detector Resolution p=20 GeV, SIMDET LDC p=20 GeV p=3 GeV p=100 GeV

14. 14 Recoil Mass (GeV)

15. 15 Recoil Mass (GeV)

16. 16

17. 17 Muon Energy (GeV) Fit for only

18. 18 Branching Ratio of H  CC   Br/Br ~ 39% (120GeV), 64% (140GeV) for Z  l+l-, 1000 fb -1 * Talk by Haijun Yang in TRK session 20Mar2005

19. 19 E beam (GeV) Beam Energy Profiles Before CollisionAfter CollisionLumi Weighted E beam (GeV) Center of Mass Energy Error Requirements Top mass: 200 ppm (35 Mev) Higgs mass: 200 ppm (60 MeV for 120 GeV Higgs) Giga-Z program: 50 ppm

20. 20 E cm (GeV)  E cm = 47 MeV * Talk by Klaus Moenig in MDI session 20Mar2005

21. 21

22. 22 E cm (GeV) M  (GeV)

23. 23 E cm (GeV) M  (GeV)

24. 24

25. 25 angles only  E Z  vs b  E Z  vs a  E  vs a  E  vs b  E  SIMDET LDC  E Z  SIMDET LDC Ecm Resolution in MeV vs a or b

26. 26 angles only  E Z  vs b  E Z  vs a  E  vs a  E  vs b  E  SIMDET LDC  E Z  SIMDET LDC Ecm Resolution in MeV vs a or b

27. 27 Simdet Fast MC with this parameterization of pt resolution in place of Simdet’s emulation of LDC: SiD Detector Resolution p=20 GeV, SIMDET LDC p=20 GeV p=3 GeV p=100 GeV

28. 28 Summary Current detector designs appear well matched to envisioned physics program Choices will have to be made as realitities of detector engineering and cost are confronted – physics benchmark studies will play a crucial role. The examples of parametric studies shown here are just the beginning.