The Measurement of Single-Top Polarization with 3.2 fb-1

Ji-Eun Jung, Thomas Junk, Soo-Bong Kim
Seoul National University, Fermilab , Seoul National University

Documentation

The technique is described in our analysis public note for the 3.2fb-1 dataset..

Exotic Model (RRLL)



Cross Section Measurment

  σSM(V-A) = 1.72 (pb) ,   σExotic(V+A) = 0 (pb)

   (2.864pb "SM prediction" : hep-ph/0207055 B.W.Harris at al. )





Observed and Expected Yields


Sample (2jet) cosθ < 0 cosθ > 0
signal(L) 43.39 ± 6.26 80.01 ± 11.74
signal(R) 73.82 ± 10.49 52.57 ± 7.50
Wbb 307.27 ± 92.65 297.32 ± 89.65
Wcc+Wc 256.23 ± 79.03 247.26 ± 76.26
Mistag 220.91 ± 30.91 233.49 ± 32.68
ttbar 73.12 ± 10.62 91.37 ± 13.27
Z+jets 13.37 ± 2.06 14.52 ± 2.23
Diboson 45.41 ± 4.69 32.89 ± 3.40
nonW 41.91 ± 16.77 40.28 ± 16.12
total BG 958.22 ± 173.19 957.14 ± 173.0
data 1001 1007
Sample (3jet) cosθ < 0 cosθ > 0
signal(L) 16.21 ± 2.35 20.88 ± 3.04
signal(R) 23.23 ± 3.29 14.82 ± 2.11
Wbb 98.19 ± 29.68 74.81 ± 22.61
Wcc+Wc 71.56 ± 22.06 56.53 ± 17.43
Mistag 63.98 ± 9.14 66.21 ± 9.45
ttbar 200.67 ± 29.04 172.43 ± 24.95
Z+jets 5.764 ± 0.85 5.03 ± 0.74
Diboson 14.87 ± 1.48 9.83 ± 1.03
nonW 17.36 ± 6.95 15.84 ± 6.34
total BG 472.39 ± 58.59 400.68 ± 49.70
data 421 457

Systematics

Systematic Uncertainties Rate Shape
Jet Energy Scale 0...16% O
Initial State Radiation 0...11% O
Final State Radiation 0...15% O
Parton Distribution Functions 2...3% O
Monte Carlo Generator 1...5%
Event Detection Efficiency 0...9%
Luminosity 6%
Neural Net B-tagger O
Mistag Model O
Non-W Model O
Non-W normalization 40%
Q2 scale in Alpgen MC O
Monte Carlo Mismodeling O
Wbb+Wcc normalization 30%
Wcj normalization 30%
Mistag normalization 17...29%
ttbar normalization 12%
MC Statistics bin-by-bin

Plots

Plots add all lepton categories together. All model contributions have been scaled to prediction.

t-channel 2 and 3 jet bin Likelihood Functions

2-jet bin



3-jet bin



2 jet bin Likelihood input variables (cosθ > 0)

2 jet bin Likelihood input variables (cosθ < 0)

3 jet bin Likelihood input variables (cosθ > 0)

3 jet bin Likelihood input variables (cosθ < 0)

Contact the authors: ici@fnal.gov, trj@fnal.gov