The Top Quark Mass measurement in the Dilepton Channel using Dynamical Likelihood Method


In 340pb-1 of CDF Run II data, we measured top quark mass
166.6 +7.3 - 6.7(stat.) ± 3.2 (syst.) GeV/c2


Authours
 Ryo Tsuchiya
Kondo Kunitaka
(Waseda University)
Abstract:

We report the top quark mass measurement by using DLM (Dynamical Likelihood Method) in the Top dilepton channel. The likelihood is defined as the differential cross section as a function of Mtop per unit phase volume of the final partons, multiplied by the transfer function from jets to parton quantities. The likelihood in an event is summed up, and the event likelihoods are multiplied each other to get the joint mass likelihood. The maximum likelihood estimate and its uncertainty are obtained by the standard treatment. The event selection is made by so-called ``dil'' selection of the top dilepton group. The HERWIG Mt = 178 GeV/c2 Top Mass Sample is used to validate the method, and we expect a statistical uncertainty of +7.3 -6.7 GeV/c2 and a systematic uncertainty of 3.2 GeV/c2. From the 33 events observed with the integrated luminosity of 340.5pb-1, we measure 166.6 GeV/c2.
Blessed plots and numbers (December 2005):

Click on the thumbnail to get the full-size file
Description of tables and plots gif eps
Number of events after additional cuts
(all cut means inclusive additional cuts
 to standard dilepton cut.)
 number of events after cuts
eps
Additional cut efficiency for top mass
 Add Cut Eff eps
Dilepton acceptance for top mass
 Acc curve eps
JET Transfer function shapes
definition 		JET ET TF JET ETA TF JET PHI TF eps eps eps
MET Transfer function shapes
definition 		MET TF MET PHI TF eps eps
Mapping function for various background fractions
 mapping function
eps
Parameter of the linear fit for mapping function
 fit parameter
eps
sanity, residual(reconstruction - input), pull mean, pull width after mapping correction (6.1pb assumption)
 after mapping 61
eps
sanity, residual(reconstruction - input), pull mean, pull width after mapping correction (data case)
 after mapping in data case
eps
pull width for top quark mass after all calibaration
(6.1pb assumption, data case)
 after calibration 61
after calibration data case
eps
eps
Jet Energy Scale systematic table Jet Energy Scale
eps
Summary table for systematics
 summary table for systematics
eps
Fitted top mass to data
 Final fitted top mass
eps
expected statistical uncertainty
(red lines point data)
 expected stat error
eps
Maximum likelihood mass distribution MLM dist
eps
Ryo Tsuchiya
Last modified: Sat Dec 10 15:56:12 JST 2005