eprintid: 35037 rev_number: 13 eprint_status: archive userid: 8238 dir: disk0/00/03/50/37 datestamp: 2024-07-02 09:03:09 lastmod: 2024-07-02 11:13:08 status_changed: 2024-07-02 09:03:09 type: doctoralThesis metadata_visibility: show creators_name: Bartels, Falk title: Search for Low-Mass Dijet Resonances Using Trigger-Level Jets at the ATLAS Detector subjects: ddc-530 divisions: i-130700 adv_faculty: af-13 keywords: ATLAS, Trigger cterms_swd: LHC cterms_swd: Dunkle Materie abstract: Conventional dijet resonance searches at the Large Hadron Collider are statistically limited for sub-TeV resonance masses by the bandwidth of the data acquisition systems. The presented search explores this mass range at unprecedented statistical precision by utilizing a partial event readout onsisting of jets reconstructed by the ATLAS High-Level Trigger using only calorimeter information. Proton-proton collisions at a centre-of-mass energy of √s = 13TeV corresponding to an integrated luminosity of up to 132 fb−1 are analyzed. A dedicated calibration for the trigger-level jets is applied and two complementary, data-driven background estimates with very high statistical precision are presented. No significant excess over the background expectation is observed and exclusion limits on dijet resonance cross sections are derived. These represent the most stringent constraints on narrow, Gaussian-shaped dijet resonances in the mass range of 375–1200 GeV in general and in the range of 375–1500 GeV for an axial-vector Dark Matter mediator coupling to quarks in particular. date: 2024 ppn_swb: 1893130657 own_urn: urn:nbn:de:bsz:16-heidok-350379 date_accepted: 2024-06-21 advisor: HASH(0x55fc2e14f748) language: eng bibsort: BARTELSFALSEARCHFORL full_text_status: public place_of_pub: Heidelberg citation: Bartels, Falk (2024) Search for Low-Mass Dijet Resonances Using Trigger-Level Jets at the ATLAS Detector. [Dissertation] document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/35037/1/PhD-Thesis_FalkBartels.pdf