Master Thesis

PUBDB-2018-05085

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Measuring Vector Boson Scattering at the future International Linear Collider

Beyer, J. (Corresponding author)DESY* ; Kobel, M. (Thesis advisor) ; List, J. (Thesis advisor)DESY*

2018

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Please use a persistent id in citations: doi:10.3204/PUBDB-2018-05085

Abstract: Vector boson scattering (VBS) is considered a well-motivated target in the search for physics beyond the Standard Model (BSM). Setting stringent limits on BSM physics inthe Higgs and electroweak sector requires precision measurements of VBS. This is best done in the clean and controlled environment at high-energy electron-positron colliders.In this work, the sensitivity of the International Linear Collider (ILC) to VBS in hadronic final states is studied at √s = 1 TeV in the International Large Detector (ILD). Datasets from full detector simulations are used for this study.A key aspect of this analysis is the separation of the WW and ZZ final state. In the hadronic final state, this is done primarily through reconstructed boson masses. Themass peaks of the WW and ZZ final states are found to be well separated, but inconsistencies with previous studies are observed. Problems in the final state reconstruction are identified to originate from heavy jet reconstruction as well as jet clustering.Neutrino corrections for heavy quark jets are investigated. A promising approach based on the average kinematics in semi-leptonic decays is identified.The peak separation is tested for two versions of the ILD - a large and a small model - and found to not be visibly influenced.First steps towards a VBS analysis in an EFT framework are taken. No optimization of the cut analysis or application of corrections to heavy jets are done in this step, but are identified as important aspects of future analyses. Sensitive observables are extracted for reconstructed WW and ZZ signal regions. Significances of S/√B = 104 for WW final state events and 40 for ZZ events are observed.Assumptions made in recent theory-level studies which predict a sensitivity between 2 and 4 times better than current LHC analyses are confirmed to be roughly valid.

Note: Masterarbeit, Technische Universität Dresden, 2018

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Contributing Institute(s):

1. Experimente an Lepton Collidern (FLC)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF3-611) (POF3-611)
2. SFB 676 B01 - Optimierung des ILC setups: Physikprogramm, Betriebsszenarien und Designentscheidungen (B01) (28895157) (28895157)

Experiment(s):

1. Facility (machine) ILC

Appears in the scientific report 2018

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Database coverage:

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