Alexandria Digital Research Library

Scalar Top Quark Search with Jets and Missing Momentum in pp Collisions at 7 TeV

Author:
D'Alfonso, Mariarosaria
Degree Grantor:
University of California, Santa Barbara. Physics
Degree Supervisor:
Joseph Incandela
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2012
Issued Date:
2012
Topics:
Physics, Elementary Particles and High Energy
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2012
Description:

The results of CMS searches for Supersymmetry are interpreted in the context of Simplified Models. A limited set of hypothetical particles and decay chains are introduced to produce a given topological signature. The amplitudes describing the production and decays of these particles are parametrized in terms of the particle masses and their branching ratios to daughter particles. Among the new possible particles, the Higgs mechanism of electroweak symmetry breaking gives a special role to the partner of the third generation SM particles. In this thesis, I will describe how the comparison of different search strategies on multiple simplified models helps to quantify that the LHC has not put any stringent bounds on them yet. The 4.98 fb-1 of data collected by CMS, was analyzed to search for the scalar stop in the jets plus met final state. In particular, I will focus on the ttbar background; I will describe in detail the handles used to reduce it and the technique adopted to predict this contribution from data. The data is found to be in agreement with the predicted backgrounds. An upper limit on the cross section times branching ratio is set for the decays stop to LSP plus top and stop to LSP plus b W through a chargino final state.

Physical Description:
1 online resource (106 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f37s7kq0
ISBN:
9781267933775
Catalog System Number:
990039502970203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Mariarosaria D'Alfonso
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