1. W/Z Plan For Winter Conferences Tom Diehl FNAL @ Saclay 12/2001

2. W/Z Group’s Charge  Goals for spring conferences:  Z  (ee) Mass & Cross Sections  W  (e  Transverse Mass and Cross Sections  W   (e  ) Event Displays  My take on these goals: Selected because they demonstrate that the upgraded detector is shaping up: u Show that the new muon detectors and trigger will do their jobs u It’s Most important that we demonstrate the capabilities of the new central tracker.

3. W/Z Group’s Charge  Ambitious u We will achieve the results in the electron channels with O(100’s) of events. u Muons are more challenging because we’ve been limited by the trigger bandwidth and because the CFT trigger is late.  Z  definitely, maybe W   Use the Tracker! Why? u Z’s and W’s are cleaner. u pT resolution is much better than the rest of the muon detector u We will be using it in the long run We should learn to use it now.

4. WZ Group’s Plan  Data Collection: u WZ_Reco (see Georg’s talk) u La Macchina (Selecting from Reco_S events)  Efficiency Calculation u The plan - what we are doing: u I wrote down some equations - shows my bias for using the tracker in the selection  Background Estimate u Examples

5. Efficiency Calculation Efficiency For W’s Efficiency For Z’s  Partly from Monte Carlo. u Monte Carlo calculates acceptance & kinematic selection u Monte Carlo doesn’t model the detector performance  Partly from Data u Use Data whenever possible u See above in reverse for Data

6. Efficiency Calculation  “Loose” is fraction of signal which passes the “Loose” selection criteria in MC.  “Tight” is efficiency of “Tight” cuts w.r.t. “Loose” cuts. u 5 components u Take care that all of “Loose” is in the denominator u Take care: there are several ways for one muon to be reconstructed as two or more s The multiple NSEG thing s Multi-region muons

7. Efficiency Calculation  For W’s, “Trigger” is efficiency of L1 for a single “Tight” muon s For instance, compare the number of events with a reconstructed “Tight” muon that pass the MU-EM trigger with the number of those that pass the 1-EM trigger s With any kind of luck there will be a L3 component to this with an efficiency close to 1.0  For Z’s, “Trigger” is a little more complicated because it involves “Tight” and “Loose” muons: s “Loose” allowed us to miss an A or BC scintillator hit s so it’s not quite “Trigger 2 ”

8. Efficiency Calculation  “Track” is probability to reconstruct and match the gtrk u Has anybody tried this?  “Isolation” is the probability for a muon from W or Z to be isolated. u Monte Carlo doesn’t yet model delta-phi very well so we have to get this from the data. s For instance, select events with two isolated high pT central tracks, two tight muons, and at least one isolated one isolated muon. Look at other muon. u Definition of Isolation:

9. W/Z Group MC Requests  Muon-Relevant Samples  50,000 W   20,000 Z  *   10,000 W  (all channels)  10,000 Z/  *  (all channels)  Characteristics u Pythia Generated u Geant Version s Plate-Level Simulation s Most Recent D0Gstar Geometry (including CF Bottom B-layer PDT rotation fix) s Zero extra interactions u Reco’d with p10.13 or later

10. W Backgrounds  Combinatoric & Cosmic u Small if CFT is used? Prove it. Hint: Use Cosmic Ray Runs.  W  +X  +X u Get this from the MC with a similar calculation used to measure the efficiency.  Muons from heavy quark decay u Determine this from the data. The background: Jets are away or too low ET

11. W  Bkgd. Setup 2Tag IsolTagged (Don’t look at jets) 1Tag0 Tags

12. W  Backgrounds  With events that pass same trigger, muon ID criteria, etc …  3 Samples (Using 1/2 detector as Tagged-Side) 2Tag IsolTagged (Don’t look at jets) 1Tag Keeping track of sides, you can get 2X more stats than this.

13. Z Backgrounds  Combinatoric & Cosmic u Small if CFT is used? Prove it. Hint: Use Cosmic Ray Runs.  Z  +X  +X u Get this from the MC with a similar calculation used to measure the efficiency.  Muons from heavy quark decay u Determine this from the data as with the W’s.

14. Summary  Goals for spring conferences:  Z  (ee) Mass & Cross Sections  W  (e  Transverse Mass and Cross Sections  W   (e  ) Event Displays  My take on these goals: u Show that the new muon detectors and trigger will do their jobs u It’s Most important that we demonstrate the capabilities of the new central tracker.