The year 2010 saw the Large Hadron Collider (LHC) collect 35:1 pb-1 of 7TeV
proton-proton collision data. This thesis reports on the work carried out by the
candidate as part of the calculation of the first constraints placed upon the supersymmetric
parameter space using measurements made with this data. In particular,
the development and application of the kinematic techniques used to ensure that
the search was robust to detector mismeasurements, inherent in any early phase of
data-taking, are discussed.
The Constrained Minimally Supersymmetric Standard Model (CMSSM) is introduced
to demonstrate how supersymmetry may extend the Standard Model of particle
physics, and is used as the benchmark signal to investigate how supersymmetry
may appear in 7TeV proton-proton collisions. The role of kinematics in early
searches for such signals is then discussed; given the final state topology of interest
(particle jets and large missing transverse momentum), particular attention is
paid to errors that are due to detector mismeasurements, and how these may be
accounted for with an appropriate choice of observable.
A search strategy based upon these principles and applied to the Compact Muon
Solenoid (CMS) experiment is then described, as used in the first published search
for supersymmetry with LHC data reported in Phys. Lett. B 698 (2011) 196. The
kinematic characterisation of events discussed above is exploited to ensure that the
search is robust to mismeasurement. The thesis concludes with a summary of the
search results. The observed number of events fulfilling the signal criteria is compatible
with that expected from the Standard Model alone. The subsequent exclusion
limits, given at the 95% Confidence Level, place significantly greater constraints
upon the supersymmetric parameter space than those of previous experiments.