@misc{10481/85648,
year = {2023},
month = {7},
url = {https://hdl.handle.net/10481/85648},
abstract = {A search for flavour-changing neutral-current decays of a top quark into an up-type quark (either up or charm) and a light scalar particle X decaying into a bottom anti-bottom quark pair is presented. The search focuses on top-quark pair production where one top quark decays to qX, with X → 
, and the other top quark decays according to the Standard Model, with the W boson decaying leptonically. The final state is thus characterised by an isolated electron or muon and at least four jets. Events are categorised according to the multiplicity of jets and jets tagged as originating from b-quarks, and a neural network is used to discriminate between signal and background processes. The data analysed correspond to 139 fb−1 of proton–proton collisions at a centre-of-mass energy of 13 TeV, recorded with the ATLAS detector at the LHC. The 95% confidence-level upper limits between 0.019% and 0.062% are derived for the branching fraction 
(t → uX) and between 0.018% and 0.078% for the branching fraction 
(t → cX), for masses of the scalar particle X between 20 and 160 GeV.},
organization = {ANPCyT},
organization = {YerPhI, Armenia},
organization = {Australian Research Council},
organization = {BMWFW, Austria},
organization = {Austrian Science Fund (FWF)},
organization = {Azerbaijan National Academy of Sciences (ANAS)},
organization = {Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)},
organization = {Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)},
organization = {Natural Sciences and Engineering Research Council of Canada (NSERC)},
organization = {Canada Foundation for Innovation},
organization = {National Natural Science Foundation of China (NSFC)},
organization = {MEYS CR, Czech Republic},
organization = {National Research Foundation of Korea},
organization = {Danish Natural Science Research Council},
organization = {Centre National de la Recherche Scientifique (CNRS)},
organization = {CEA-DRF/IRFU, France},
organization = {Federal Ministry of Education & Research (BMBF)},
organization = {Max Planck Society},
organization = {Hong Kong SAR, China},
organization = {Israel Science Foundation},
organization = {Istituto Nazionale di Fisica Nucleare (INFN)},
organization = {Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT)},
organization = {Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT)
Japan Society for the Promotion of Science},
organization = {CNRST, Morocco},
organization = {RCN, Norway},
organization = {MEiN, Poland},
organization = {Fundacao para a Ciencia e a Tecnologia (FCT)},
organization = {MNE/IFA, Romania},
organization = {Ministry of Education, Science & Technological Development, Serbia},
organization = {MSSR, Slovakia},
organization = {Slovenian Research Agency - Slovenia},
organization = {MIZS, Slovenia},
organization = {Spanish Government},
organization = {Wallenberg Foundation, Sweden},
organization = {SERI, Switzerland},
organization = {Ministry of Science and Technology, Taiwan},
organization = {United States Department of Energy (DOE)},
organization = {National Science Foundation (NSF)},
organization = {BCKDF, Canada},
organization = {CANARIE, Canada},
organization = {Compute Canada, Canada},
organization = {Czech Republic Government	PRIMUS 21/SCI/017
UNCE SCI/013},
organization = {COST, European Union},
organization = {European Union (EU)
European Research Council (ERC)},
organization = {European Union (EU)
Marie Curie Actions},
organization = {Horizon 2020, European Union},
organization = {European Union (EU)
Marie Curie Actions},
organization = {Agence Nationale de la Recherche (ANR)},
organization = {German Research Foundation (DFG)},
organization = {Alexander von Humboldt Foundation},
organization = {Herakleitos programme - EU-ESF, Greece},
organization = {Thales Group},
organization = {Aristeia programme - EU-ESF, Greece},
organization = {Greek NSRF, Greece},
organization = {BSF-NSF, Israel},
organization = {MINERVA, Israel},
organization = {Norwegian Financial Mechanism 2014-2021, Norway},
organization = {NCN, Poland},
organization = {Polish National Agency for Academic Exchange (NAWA)},
organization = {La Caixa Banking Foundation, Spain},
organization = {CERCA Programme Generalitat de Catalunya, Spain},
organization = {PROMETEO Programme Generalitat Valenciana, Spain},
organization = {GenT Programme Generalitat Valenciana, Spain},
organization = {Goran Gustafssons Stiftelse, Sweden},
organization = {Royal Society},
organization = {Leverhulme Trust},
organization = {UK Research & Innovation (UKRI)
Science & Technology Facilities Council (STFC)},
organization = {TENMAK, Turkiye},
organization = {Canton of Geneva, Switzerland},
organization = {Canton of Bern, Switzerland},
organization = {Swiss National Science Foundation (SNSF)},
organization = {SRC, Sweden},
organization = {DSI/NRF, South Africa},
organization = {Netherlands Organization for Scientific Research (NWO)
Netherlands Government},
organization = {Benoziyo Center, Israel},
organization = {RGC, China},
organization = {GSRI, Greece},
organization = {HGF, Germany},
organization = {SRNSFG, Georgia},
organization = {Minciencias, Colombia},
organization = {Ministry of Science and Technology, China},
organization = {Chinese Academy of Sciences},
organization = {ANID, Chile},
organization = {CERN},
organization = {NRC, Canada},
publisher = {Springer Nature},
keywords = {Hadron-Hadron Scattering},
title = {Search for a new scalar resonance in flavour-changing neutral-current top-quark decays t ! qX (q = u, c), with X ! b¯b, in proton-proton collisions at p s = 13 TeV with the ATLAS detector},
doi = {10.1007/JHEP07(2023)199},
author = {Atlas Collaboration and Aguilar Saavedra, Juan Antonio and Rodríguez Chala, Mikael},
}