title: Measurement of the Invisible Width of the Z Boson  with the ATLAS Detector
creator: Klassen, Martin
subject: ddc-530
subject: 530 Physics
description: The measurement of the partial decay width of the Z boson into invisible particles represents a precision test of the electroweak structure of the Standard Model of particle physics. In this thesis, a measurement of the invisible Z boson width with the ATLAS detector at the Large Hadron Collider is presented using an integrated luminosity of 37 fb-1 of proton-proton collision data collected at a centre-of-mass energy of 13 TeV. Collision events with missing transverse momentum associated with at least one highly energetic jet are selected. Ratios of the obtained invisible Z boson decays to Z boson decays into pairs of oppositely charged electrons or muons, respectively, are constructed. These ratios are corrected for detector effects and combined into a ratio of branching fractions Rmiss. This ratio is then used in combination with the leptonic Z boson width, determined at the Large Electron-Positron Collider, to derive the invisible width of the Z boson. It is measured to be 506 ± 2 (stat.) ± 12 (syst.) MeV, which is in excellent agreement with the Standard Model prediction and with previous measurements. This result is the single most precise measurement of Γ_Z(inv) to date based on missing transverse momentum in the final state.
date: 2023
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/33952/1/Thesis-42-a.pdf
identifier: DOI:10.11588/heidok.00033952
identifier: urn:nbn:de:bsz:16-heidok-339526
identifier:   Klassen, Martin  (2023) Measurement of the Invisible Width of the Z Boson with the ATLAS Detector.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/33952/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng