Implementation of the DAQ software for the ALTI module in the ATLAS TileCal and the search for new physics in the four lepton final state
| dc.contributor.advisor | Wilkens, Henric | |
| dc.contributor.author | Tlou, Humphry Sijiye | |
| dc.contributor.co-supervisor | Ruan, Xifeng | |
| dc.contributor.supervisor | Mellado, Bruce | |
| dc.date.accessioned | 2024-11-22T15:21:03Z | |
| dc.date.available | 2024-11-22T15:21:03Z | |
| dc.date.issued | 2023-06 | |
| dc.description | A thesis submitted in fulfillment of the requirements for the degree of Doctor of Philosophy (in Institute for Collider Particle Physics), to the Faculty of Science, School of Physics, University of the Witwatersrand, Johannesburg, 2023. | |
| dc.description.abstract | The discovery of the Standard Model (SM) Higgs boson in 2012 presents new challenges and opportunities for the Large Hadron Collider (LHC) experiments. After a long period of operation, the LHC experiments needed to maintain and upgrade their detectors in order to continue and conduct research beyond the SM. As part of the upgrades, the Tile Calorimeter (TileCal) participated in Phase-I of the upgrades (December 2018 - March 2022). TileCal, the central hadronic calorimeter (|η| < 1.7) of the ATLAS experiment uses a set of Trigger and Data Acquisition (TDAQ) software to readout, transport and store physics data resulting from collisions at the LHC. In preparation for the Phase-I upgrades, the ATLAS Local Trigger Interface (ALTI) module was designed for the ATLAS experiment at CERN for TDAQ purposes. It is a 6U VME electronics board, which is a part of the Timing, Trigger and Control (TTC) system. It integrates the functionalities of four legacy modules, currently used in the experiment: Local Trigger Processor, Local Trigger Processor interface, TTC VME bus interface and the TTC emitter. The ALTI module provides the interface between the Level-1 Central Trigger Processor and the TTC optical broadcasting network to the front-end electronics of each of the ATLAS sub-detectors. This thesis discusses the development, validation and integration of the TileCal specific ALTI software in the TileCal online software by the author. A set of ALTI boards were installed in the back-end electronics of the sub-detector and fully validated for the ATLAS detector at CERN. Performance testing and maintenance of the ALTI modules and software were performed during the second half of the upgrade period, in preparation for Run 3 (2022–2025) data-taking period. The thesis also discusses the search for the presence of a new heavy resonance produced via gluon-gluon fusion and decaying to the four-lepton (4ℓ) final state, in association with missing transverse energy (EmissT), with ℓ = e, µ (where ℓ is the lepton, e is the electron and µ is the muon). The search uses 2015–2018 proton-proton collision data at √s = 13 TeV, corresponding to an integrated luminosity of 139 fb−1, collected by the ATLAS detector. The data are interpreted in terms of two models, firstly the R → SH → 4ℓ + EmissT , where R is a scalar boson, which decays to two lighter scalar bosons (S and H). The S decays to a pair of neutrinos and the H decays into 4ℓ, through ZZ bosons. The second model is the A → Z(νν)H(ZZ) → 4ℓ + X, where A is considered to be a CP-odd scalar which decays to a CP-even scalar H and the Z boson. The Z boson decays to X, which can be a pair of neutrinos or jets, and the H decays to the 4ℓ final state. | |
| dc.description.sponsorship | National Research Foundation (NRF). | |
| dc.description.sponsorship | Department of Science and Innovation through the SA-CERN consortium. | |
| dc.description.sponsorship | SAINTS, iThemba LABS NRF, through the PhD SA-CERN Excellence Scholarship. | |
| dc.description.submitter | MMM2024 | |
| dc.faculty | Faculty of Science | |
| dc.identifier | 0000-0002-4934-1661 | |
| dc.identifier.citation | Tlou, Humphry Sijiye. (2023). Implementation of the DAQ software for the ALTI module in the ATLAS TileCal and the search for new physics in the four lepton final state. [PhD thesis, University of the Witwatersrand, Johannesburg]. https://hdl.handle.net/10539/42849 | |
| dc.identifier.uri | https://hdl.handle.net/10539/42849 | |
| dc.language.iso | en | |
| dc.publisher | University of the Witwatersrand, Johannesburg | |
| dc.rights | ©2023 University of the Witwatersrand, Johannesburg. All rights reserved. The copyright in this work vests in the University of the Witwatersrand, Johannesburg. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of University of the Witwatersrand, Johannesburg. | |
| dc.rights.holder | University of the Witwatersrand, Johannesburg | |
| dc.school | School of Physics | |
| dc.subject | Detectors | |
| dc.subject | TDAQ systems, Software | |
| dc.subject | ALTI module | |
| dc.subject | Particle Physics | |
| dc.subject | UCTD | |
| dc.subject.other | SDG-9: Industry, innovation and infrastructure | |
| dc.title | Implementation of the DAQ software for the ALTI module in the ATLAS TileCal and the search for new physics in the four lepton final state | |
| dc.type | Thesis |