% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Sahin:320460,
author = {Sahin, Mehmet Ozgur},
othercontributors = {Melzer-Pellmann, Isabell and Schleper, Peter},
title = {{S}earch for {S}upersymmetric {T}op-{Q}uark {P}artners
{U}sing {S}upport {V}ector {M}achines and {U}pgrade of the
{H}adron {C}alorimeter {F}ront-{E}nd {R}eadout {C}ontrol
{S}ystem at {CMS}},
school = {Universität Hamburg},
type = {Dissertation},
address = {Hamburg},
publisher = {Verlag Deutsches Elektronen-Synchrotron},
reportid = {PUBDB-2017-01744, DESY-THESIS-2017-014},
series = {DESY-THESIS},
pages = {171},
year = {2017},
note = {Dissertation, Universität Hamburg, 2016},
abstract = {In this thesis a search for direct pair production of
supersymmetric top-quark partners as well as work on the
upgrade of the front-end readout controller of the Hadron
Calorimeter (HCAL) of the Compact Muon Solenoid (CMS)
experiment are presented. The most appealing extension of
the Standard Model (SM) is supersymmetry (SUSY), relating
the integer spin (bosons) and half-integer spin elementary
particles (fermions). Supersymmetric top-quark partners (top
squark) around and below the TeV energy scale offer a
solution to the hierarchy problem. Furthermore, R-parity
conserving SUSY models propose a cold dark matter candidate
in the form of stable lightest supersymmetric particles
(LSP), eg lightest neutralinos. The analysis performed in
this thesis is a search for top-squark pair production in a
final state consisting of a single isolated lepton, jets,
among which at least one is tagged as bottom-quark jet, and
large missing transverse energy at the CMS experiment at the
CERN Large Hadron Collider (LHC) with 8 TeV center-of-mass
energy. A new Support Vector Machines (SVM) High-Energy
Physics interface (SVM-HINT) software is introduced to
classify signal events originating from new physics
processes and the SM background. SVM-HINT is enhanced with a
novel statistical significance based optimization algorithm
providing a state-of-the-art classification power. Monte
Carlo simulations are used in the training and optimization
procedure, and high signal purity search regions are
determined in the search for top-squark pair production. The
background event yields in each search region are predicted
using a data-driven background estimation method. The
results are interpreted within a simplified model assuming a
top squark branching ratio of $100\%$ to top-quark and LSP.
No significant discrepancy between the data and the SM
predictions has been observed. Exclusion limits were derived
to constrain the mass of top squark and mass of LSP of the
investigated simplified model. The sensitivity of the
previous searches with the 8 TeV center-of-mass energy in
the single lepton final states is extended to 675 GeV top
squark mass and 225 GeV LSP mass.},
cin = {CMS},
cid = {I:(DE-H253)CMS-20120731},
pnm = {611 - Fundamental Particles and Forces (POF3-611) / PHGS,
VH-GS-500 - PIER Helmholtz Graduate School
$(2015_IFV-VH-GS-500)$},
pid = {G:(DE-HGF)POF3-611 / $G:(DE-HGF)2015_IFV-VH-GS-500$},
experiment = {EXP:(DE-H253)LHC-Exp-CMS-20150101},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
doi = {10.3204/PUBDB-2017-01744},
url = {https://bib-pubdb1.desy.de/record/320460},
}