1. Outline Physics Motivation Technique Results
IPP Paper Reading: Measurement of the Top Quark Mass with the Dynamical Likelihood Method Using b-Tagged Lepton plus Jet Events in ppbar Collisions at sqsrt(s) = 1.96 TeV
Outline
Physics Motivation
Technique
Results
Pekka K. Sinervo,F.R.S.C.
Department of Physics
University of Toronto
9 Sep 05
CDF Paper Reading

2. Why the Cross Section? The top quark mass
One of the essential parameters in the standard model
Due to loop corrections:
W and Z boson masses related to top quark and Higgs boson masses
CDF Paper Reading

3. DLM Event Selection Top is pair-produced in pp collisions
Decays into WWbb
DLM event selection focussed on getting cleanest and largest sample
Require
Lepton Pt>20 GeV/c\
MET>20 GeV
Exactly 4 jets with Et>15 GeV
At least one SECVTX tag
Results in 63 events
Estimate 9.2±1.8 events background
Primarily QCD (non-W) and W+jets (with mistag)
CDF Paper Reading

4. Analysis Method
Use an approximate matrix-element to calculate a likelihood for each event
Parton combinatorics and detector resolution taken into account by using “Transfer Functions”
Results in a event-likelihood
Compare data and MC predictions
Excellent agreement
CDF Paper Reading

5. Results Create joint likelihood Final Result Maximize to get
Have to correct for shift due to background and scale factor:
Systematics contribute 3.2 GeV/c2
Dominated by jet systematics of 3.0 GeV/c2
Final Result
CDF Paper Reading