W/Z Plan For Winter Conferences

1
W/Z Plan For Winter Conferences

• Tom Diehl
• FNAL
• _at_ Saclay 12/2001

2
W/Z Groups Charge

• Goals for spring conferences
• Z-gt mm (ee) Mass Cross Sections
• W-gt mn (en) Transverse Mass and Cross Sections
• W-gt 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
• Its Most important that we demonstrate the
  capabilities of the new central tracker.

3
W/Z Groups Charge

• Ambitious
• We will achieve the results in the electron
  channels with O(100s) of events.
• Muons are more challenging because weve been
  limited by the trigger bandwidth and because the
  CFT trigger is late.
• Z-gtmm definitely, maybe W-gtmn
• Use the Tracker! Why?
• Zs and Ws 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 Groups Plan

• Data Collection
• WZ_Reco (see Georgs 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 Calculation

• Partly from Monte Carlo.
• Monte Carlo calculates acceptance kinematic
  selection
• Monte Carlo doesnt 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 Ws, 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 Zs, 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 its 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 doesnt 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-gt mn
• 20,000 Z/g-gt mm
• 10,000 W-gt tn (all channels)
• 10,000 Z/g-gt 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
• Recod with p10.13 or later

10
W Backgrounds

• Combinatoric Cosmic
• Small if CFT is used? Prove it. Hint Use
  Cosmic Ray Runs.
• W-gttnX-gtmnnnX
• 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
W-gtmn Bkgd. Setup
12
W-gtmn 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-gtttX-gtmmnnnnX
• 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 Ws.

14
Summary

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