|dc.contributor.author||Teixeira Dias Castanheira, Matilde||
|dc.identifier.citation||Teixeira Dias Castanheira, M. 2013. Measurement of the Single Top t-channel Cross Section Using a Cut Based Analysis With the ATLAS Detector in pp Collisions at √s = 7 TeV. Queen Mary University of London.||en_US
|dc.description.abstract||This thesis presents studies of the single top t-channel in the electron plus jets
mode. In order to understand this channel, an account of the present theoretical
models is given. This work relies on collisions data from the ATLAS detector and
its components are presented here. A summary of the work involving the SCT, part
of the tracking system in ATLAS, is also explained here. Studies were performed to
optimize the measurement of the Lorentz Angle of the holes in the Silicon for the
initial data taking period.
The data studied was acquired by ATLAS during 2011, with a total integrated
luminosity of 4.7 pb−1 at a √s = 7 TeV. Monte Carlo simulation of signal and
background events was also used throughout.
Background studies were performed to correctly determine the expected amount
of QCD via the Jet Electron data-driven method and of light or heavy flavour jets
produced in association with a W boson, which is one of the dominant backgrounds
for the t-channel.
A cut based analysis was then applied to the data and simulation in order to
better discriminate the t-channel signal. A binned likelihood fit to the invariant
mass of the reconstructed top quark was performed and the cross section value for
the t-channel process was calculated: σt−channel = 62.2±8.0(stat)+8.6
−8.8(syst) pb which
is in good agreement with the theoretically predicted value.
Finally, the response (preco
T ) of light quark or gluon initiated jets is evaluated for both the t-channel and the Wt associated production, in order to determine
the flavour composition uncertainty, as part of the framework that provides the jet
energy scale uncertainties in a multiple jets environment. Other sources of system-
atics are also reviewed.||en_US
|dc.description.sponsorship||FCT project SFRH/BD/40251/2007.||
|dc.publisher||Queen Mary University of London||
|dc.subject||School of Biological and Chemical Sciences||en_US
|dc.title||Measurement of the Single Top t-channel Cross Section Using a Cut Based Analysis With the ATLAS Detector in pp Collisions at √s = 7 TeV||en_US
|dc.rights.holder||The copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the author||