In this thesis we present a measurement of the relative fraction of ttbar 
events produced via gluon-fusion to the total number of ttbar events.  Using 
the kinematics of the production and decay of the top and antitop quark pair, 
we trained a Neural Network to discriminate the gluon-fusion events.  The 
Neural Network was then used as a template to fit for the gluon-fusion 
fraction in data.  Using a total integrated luminosity of 955~pb$^{-1}$ we 
find the fraction of gluon-fusion event in all ttbar events to be < 0.33 at the 
68% confidence level and < 0.61 at the 95% confidence level.


Posted to:
  /cdf/www/pub/thesis/cdf8991_jyamaoka_thesis_1.ps
      http://www-cdf.fnal.gov/thesis/cdf8991_jyamaoka_thesis_1.ps
  /cdf/www/pub/thesis/cdf8991_jyamaoka_thesis_2.pdf
      http://www-cdf.fnal.gov/thesis/cdf8991_jyamaoka_thesis_2.pdf

Posted by yamaoka