Using 1.0 fb^{-1} of data collected by the Collider Detector at Fermilab (CDF) from
Run II of the Fermilab Tevatron, we
measure the top-antitop production cross-section in events with two leptons,
significant missing transverse energy, and at least jets, at least one
of which is identified as a b-jet.
As the Run II dataset grows, more stringent tests of Standard Model
predictions for the top quark sector are becoming possible.
The dilepton channel, where both top quarks decay t-> W b ->l nu b,
is of particular interest due to its high purity.
Use of an isolated track as the second lepton
significantly increases the
dilepton acceptance, at the price of some increase in background, particularly
from W + jets events where one of the jets is identified as a lepton.
To control the increase in background
we add to the event selection the requirement that at least one of the jets
be identified as a b-jet,
reducing the background contribution from all sources.
Assuming a branching ratio of BR(W->l nu) =
10.8% and a top mass of m_top = 175 GeV/c^{2}
the measured cross-section is
sigma = (10.5 +/- 1.8 stat. +/- 0.8 syst. +/- 0.6 lumi.) pb.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/24221 |
| Date | 01 April 2010 |
| Creators | Spreitzer, Teresa |
| Contributors | Savard, Pierre |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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