Top Mass Measurement in Dilepton Channel using Pzttbar
(Kinematic Method)


Authors:
Tuula Maki1, Jaroslav Antos2,3, Andy Beretvas4,
Yen-Chu Chen2 , Roman Lysak2,3

1) University of Helsinki and Helsinki Institute of Physics
2) Academia Sinica, Taiwan
3) Institute of Experimental Physics, Slovak Academy of Sciences
4) Fermilab



We present a top quark mass measurement in the dilepton channel using
a template method. The unconstrained system of dilepton events is solved using
the top-antitop longitudinal momentum. In this measurement, the sample is separated
into b-tagged and non-tagged samples. In 1.2 fb-1 of data, we measure the top mass

Mtop=169.7 +5.2-4.9 (stat.) ± 3.1 (syst.) GeV/c2

from the 70 events passing the event selection and the mass reconstruction.


PUBLIC NOTE
EVENT DISPLAYS
INTERNAL WEB-PAGES

ANALYSIS WITH CROSS-SECTION DEPENDENCE

Exactly the same per event mass reconstruction and templates as this analysis



send comments to authors


Blessed plots and tables:

all plots and tables are available in two formats: .gif and .eps
Description of tables and plots gif eps
B-tagged signal templates and parametrisation functions for three top masses eps
Non-tagged signal templates and parametrisation functions for three top masses eps
Combined background template and parametrisation function
eps
Longitudinal component of ttbar momentum
eps
Reconstructed top mass versus input top mass from pseudo-experiments. The fitted line is 1.007*(Mtop-175)+175.0 eps
Residuals from pseudo-experiments. The fitted average residual is 0.004+-0.093. eps
Pull means from pseudo-experiments. The fitted average pull mean is 0.008+-0.016. eps
Pull widths from pseudo-experiments. The fitted average pull width is 1.003+-0.004. eps
Reconstructed top mass distribution from data events and parametrisation functions with measured top mass. Measured top mass from 70 data events:
Mtop=169.7 +5.2-4.9 (stat.) ± 3.1 (syst.) GeV/c2
eps
Reconstructed top mass distribution from b-tagged data events. Measured top mass from 33 b-tagged events:
Mtop=171.9 +7.2-6.4 (stat.) ± 3.1 (syst.) GeV/c2
eps
Reconstructed top mass distribution from non-tagged data events. Measured top mass from 39 non-tagged events:
Mtop=166.0 +8.4-7.9 (stat.) ± 3.1 (syst.) GeV/c2
eps
Expected statistical error from pseudo-experiments eps
Systematic errors Systematic uncertainties
Source &Delta Mtop(GeV/c2)
Jet energy scale 2.9
B-et energy scale 0.5
Lepton energy scale 0.2
MC generator 0.3
ISR 0.2
FSR 0.4
PDF 0.6
B-tagging ET dependence 0.1
Sample composition 0.3
Signal MC statistics 0.2
Background MC statistics 0.5
Background template shape 0.3
Total 3.1

Last modified: Sun July 15 17:49:03 CEST 2007