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W/Z Plan For Winter Conferences

W/Z Plan For Winter Conferences

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W/Z Plan For Winter Conferences

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

  2. W/Z Group’s Charge • Goals for spring conferences: • Z-> mm (ee) Mass & Cross Sections • W-> mn (en) Transverse Mass and Cross Sections • W->mg (eg) Event Displays • My take on these goals: Selected because they demonstrate that the upgraded detector is shaping up: • Show that the new muon detectors and trigger will do their jobs • It’s Most important that we demonstrate the capabilities of the new central tracker.

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

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

  5. Efficiency For W’s Efficiency For Z’s Efficiency Calculation • Partly from Monte Carlo. • Monte Carlo calculates acceptance & kinematic selection • Monte Carlo doesn’t model the detector performance • Partly from Data • Use Data whenever possible • 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. • 5 components • Take care that all of “Loose” is in the denominator • Take care: there are several ways for one muon to be reconstructed as two or more • The multiple NSEG thing • Multi-region muons

  7. Efficiency Calculation • For W’s, “Trigger” is efficiency of L1 for a single “Tight” muon • 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 • 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: • “Loose” allowed us to miss an A or BC scintillator hit • so it’s not quite “Trigger2”

  8. Efficiency Calculation • “Track” is probability to reconstruct and match the gtrk • Has anybody tried this? • “Isolation” is the probability for a muon from W or Z to be isolated. • Monte Carlo doesn’t yet model delta-phi very well so we have to get this from the data. • 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. • Definition of Isolation:

  9. W/Z Group MC Requests • Muon-Relevant Samples • 50,000 W-> mn • 20,000 Z/g*-> mm • 10,000 W-> tn (all channels) • 10,000 Z/g*-> tt (all channels) • Characteristics • Pythia Generated • Geant Version • Plate-Level Simulation • Most Recent D0Gstar Geometry (including CF Bottom B-layer PDT rotation fix) • Zero extra interactions • Reco’d with p10.13 or later

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

  11. 0 Tags 2Tag 1Tag IsolTagged (Don’t look at jets) W->mn Bkgd. Setup

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

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

  14. Summary • Goals for spring conferences: • Z-> mm (ee) Mass & Cross Sections • W-> mn (en) Transverse Mass and Cross Sections • W->mg (eg) Event Displays • My take on these goals: • Show that the new muon detectors and trigger will do their jobs • It’s Most important that we demonstrate the capabilities of the new central tracker.