Book/Dissertation / PhD Thesis

PUBDB-2024-01900

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png First simultaneous measurement of single and pair production of top quarks in association with a Z boson at the LHC

Colombina, F. C. (Corresponding author)Extern*DESY* ; Meyer, A. (Thesis advisor)DESY* ; Haller, J. (Thesis advisor)Extern*

2024
Verlag Deutsches Elektronen-Synchrotron DESY Hamburg

This record in other databases:

Please use a persistent id in citations: urn:nbn:de:gbv:18-ediss-118202  doi:10.3204/PUBDB-2024-01900

Report No.: DESY-THESIS-2024-007

Abstract: In the years 2016–2018 the CMS Experiment at CERN’s Large Hadron Colliderrecorded a large amount of proton-proton collision data at a centre-of-mass energyof 13 TeV, corresponding to an integrated luminosity of 138 fb−1.With this large dataset, the associated production of top quarks with the Z bosonhas been measured precisely and differentially. In this thesis, for the first time,single and pair production of top quarks in association with a Z boson (tZq, tWZand ttZ) are measured simultaneously and differentially. A multiclass deep neuralnetwork is used to separate the signal processes and the backgrounds. The interferencebetween ttZ and tWZ complicates their separation, and therefore their sumis reported in the results. Compared to previous studies, the simultaneous measurementis less dependent on the signal modeling assumptions and improves thesensitivity to new physics scenarios, as it enables to constrain possible deviationsfrom the standard model across different processes.Studies on muon identification methods with the CMS detector are also presented,with particular focus on novel techniques to correct discrepancies between simulationand the data.

Note: Dissertation, Universität Hamburg, 2024

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Contributing Institute(s):

1. LHC/CMS Experiment (CMS)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)
2. PHGS, VH-GS-500 - PIER Helmholtz Graduate School (2015_IFV-VH-GS-500) (2015_IFV-VH-GS-500)

Experiment(s):

1. LHC: CMS

Appears in the scientific report 2024

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