MD Contribution to Simulation and W Width/Mass

1. MD Contribution to Simulation and W Width/Mass Sarah Eno 30 Aug 2005 DOE Review Sarah Eno

2. Simulation • MD has made major contributions to simulation code for Dzero. • Sarah Eno (professor) • Shuichi Kunori (Research Scientist) • Greg Graham (former postdoc, now FNAL computing division) • Marco Verzzochi (former postdoc, now Wilson Fellow) • Junjie Zhu (former student, now postdoc at Stony Brook) • Lei Wang (current student) • Matt Wetstein (current student) • Christie Chew (former undergrad) Sarah Eno

3. Major Projects • Develop and main responsibility for fast simulation code (Sarah, Greg, Junjie, Marco) • Developing and debugging “d0raw2sim” (Sarah, Christie) • initial C++ “wrapper” for GEANT-3 based simulation and general GEANT expert (Shuichi) • code to test and validate new releases of full simulation (Lei) • Sarah was co-head of the simulation group from 2003-2005. Sarah Eno

4. Last Year Full simulation. Sarah worked with the developers to implement the following changes. Lei found bugs for them with his certification package. • Martijn Mulders of FNAL updated the muon geometry • Sudeshna Banerjee of the Tata institute updated the SMT cable geometry. These changes also had to be coordinated with the geometry used in the reconstruction. • Sahal Yacoob of Northwestern updated the beam pipe geometry • Mike Hildreth of Notre Dame updated the geometry of the fiber tracker • Alice Bean of the University of Kansas updated the noise and cross-talk simulation of the silicon tracker. Sarah Eno

5. D0Raw2Sim • Process real zero bias data, to put them into a format so that they can be overlaid (via pileup, which is linked into D0Sim) onto signal MC. • Benefits: better simulation of noise (especially in calorimeter) and of the soft physics of the pileup interactions. • Problems: Overlaying data onto MC is a problem for code that has if(MC). Part of the event wants the MC settings, part the data. Our code has a lot of this: • geometry • time to distance relations • etc Non-trivial!! Sarah Eno

6. Last Year • Sarah spent a lot of time with Mike Hildreth debugging the code for the fiber tracker, and some time with Alex Melnitchouk (Mississippi) and Avto Kharchilava (Buffalo) debugging the SMT code • Sarah worked with Bob Hirosky (Virginia) to develop tools for processing the zero bias data needed for this project. • Results from 2 types of tests: • Is it doing a good job of translating from data to MC format? How badly are the if(MC) statements hurting the result? • How does it compare with the traditional method of doing pileup (since that has its own problems)? Sarah Eno

7. Test of if(MC) problem Path 1 (black): process zero bias data with reco + recocert (data rcps) Path 2 (red) process zero bias data through d0raw2sim and overlayed onto single neutrino events and process with reco+recocert (MC rcps) Results should beIDENTICAL. Remember, d0raw2sim just translates from one format to another. Nothing more. However, remember, this shows how the pileup is messed up. The hits from the signal *will* be handled correctly (since they really are MC, and I processed using the MC rcp’s) Sarah Eno

8. Calorimeter Black: no d0raw2sim Red: d0rawsim Sarah Eno Sarah Eno

9. Fast Simulation Sarah (with Lee Lueking of FNAL) wrote the Run I fast simulation. Sarah (with Greg Graham) wrote the Run II fast simulation. Fast simulation is used for almost all EWK results, and some NP results. Top group is trying to adapt it for their needs. Sarah Eno

10. Fast Simulation Sarah Eno

11. W Width/Mass Analysis Marco Verzocchi (former postdoc) head of D0 EWK group from 2002 to 2004 Sarah and Marco head of W mass group from 2002 to 2005 Junjie Zhu (former student) completed thesis on W mass in October, 2004 (approved for conferences Aug 2004) Junjie/Marco also made major contributions to the W/Z cross sections to electrons analysis Matt Wetstein (current student) working on W mass thesis Michiel Sanders (current postdoc): tracking scale and mass in the muon channel Sarah on EB for cross sections analysis Sarah Eno

12. Marco Junjie W Z Cross Sections • Preliminary to all W/Z analyses • Test of QCD • can be used to extract an indirect measurement of the W width Thesis of John Gardener, Kansas Junjie made major contributions/cross checks to code that calculates the acceptance, fast Monte Carlo, efficiency calculations, backgrounds, resolutions Marco did most of the work on data sample preparation, luminosity calculation Sarah Eno

13. W/Z Cross Sections 177 pb-1 Sarah Eno

14. W/Z Cross Sections Close to publication Sarah Eno

15. measure extract LEP theory Indirect Width (MD also did the Run I measurement) Sarah Eno

16. Run II Run II Indirect 2.5% measurement in Run I 2nd most precise measurement from the Run I data Sarah Eno

17. t H W W Dr~Mt2 W Dr~ln MH W W W Mass/Width One of the best ways we have to constraint the Higgs mass before its discovery Sarah Eno

18. W’s LEP EWWG Sarah Eno

19. Mass Highest precision measurement will come from the Tevatron’s Collider. Sarah Eno

20. W Width: Why? Tree level Not so useful for Higgs physics, but there is a way of doing the measurement that is a useful step towards the mass measurement. Sarah Eno

21. W Width Technique same as W mass measurement, but has large stat error Same data sample, MC, as cross section analysis Sarah Eno

22. W Width Have not published yet because… DPF 2005 Sarah Eno

23. Calorimeter Calibration 3.3 GeV 2.2 GeV Sarah Eno

24. MD+ Jan Stark Calorimeter Calibration • Two Aspects of Calibration: • ● Electronics Calibration Using Pulsers • ●Nonlinearity corrections for SCAs (switched capacitor arrays) • ●Gain-corrections • ●Pedestals, baseline subtraction (and their stability in time) • ● Calibration of the Physical Device • ●Nonuniformities in the detector construction. In Run II, with shorter integration time and lower readout voltages we are more sensitive to these effects. • ●Not enough Z→ee to calibrate out these effects on sufficiently small granularities • ●Instead, we look to more abundant samples to improve the statistical power of ourcalibration Sarah Eno

25. Method We require Emin > Etrigger 2) Count the number of events in each tower 3) Adjust the energy cut Ei for each tower until the occupancy of the tower equals the average occupancy for the phi ring. We expect approximate phi symmetry. 4) Assuming a proportional energy response, our towerlevel calibration constants are given by a single multiplicative constant: αi = Ei/Emin Sarah Eno

26. Calorimeter Calibration Data Sample ● Level 1: CEM(1,6) : EM trigger towers with ET>6 GeV ● No Level 2 ● Level 3: Precision towers with ET >8 GeV matched to the L1 trigger ● No bias from clustering at L3 ● Prescales were adjusted to saturate the DAQ. We found that this would provide sufficient data in one store to intercalibrate CC towers to within 1% ● August 2004, we had 20 hours of beamtime...collected 5.5 million events trigger is now a part of normal physics running Sarah Eno

27. Calibration Constants Sarah Eno

28. Calorimeter Calibration 2.93 GeV 3.35 GeV HCAL is now being calibrated using same method (different people) 2.99 GeV Sarah Eno

29. W Mass with Muons • Muon and electron channels are complimentary: • Electron channel is mostly Calorimeter based • Muon channel is mostly Tracking based • Partly independent systematics • Additional statistical power • Caveat: momentum resolution of tracking is not as good as calorimeter Unfortunately, the Fundamentals need work first here as well. (M. Sanders) Sarah Eno

30. Tracking Scale • Muon momentum measured by central tracking detectors • Need to understand momentum measurement of tracking detectors: • Magnetic field • Passive material inside the detector: energy loss • Linearity, momentum resolution • Final momentum scale will be determined with Z events • Use large samples of J/Y's and Kshort’ss to study details Sarah Eno

31. Problems Sarah Eno

32. Tracking & Material • Energy loss of a muon in material is mostly through ionization and atomic excitation, described by Bethe-Bloch formula: • 􀀀 • Study additional correction needed as function of energy -> add the correct amount of material to the track reconstruction • see if this improves our understanding Sarah Eno

33. Tracking Sarah Eno

34. Tracking & Material Sarah Eno

35. Z PT Lei Wang’s thesis work Important input to W mass Test of QCD Complement to Toole/Yan analysis Sarah Eno

36. Z PT Test of method using MC Lei is first student in W/Z group to look at the new “P17” data Sarah Eno

37. ZZ Production Thesis topic of Chad Jarvis Important background for Higgs Production Sarah Eno

38. ZZ Sarah Eno

39. ZZ Sarah Eno

40. TeV EWWG In the spring of 2003, Sarah Eno, Martin Grunewald (Dublin), Ashutosh Kotwal (Duke) and Michael Schmitt (Northwestern) founded the Tevatron Electroweak Working Group, modeled on the LEP EWWG. Goal: provide prompt, correct preliminary combinations of EWK results from the Tevatron (including top mass). Encourage communication between CDF and D0 on theoretical issues, error catagories, etc. Sarah Eno