Search for heavy particles in the b-tagged dijet mass distribution with additional b-tagged jets in proton-proton collisions at √s=13 TeV with the ATLAS experiment

Abstract

We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; Minciencias, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRI, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; MES of Russia and NRC KI, Russian Federation; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada and CRC, Canada; COST, ERC, ERDF, Horizon 2020 and Marie Skłodowska-Curie Actions, European Union; Investissements d'Avenir Labex, Investissements d'Avenir Idex and ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF, Greece; BSF-NSF and GIF, Israel; Norwegian Financial Mechanism 2014–2021, Norway; La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya and PROMETEO and GenT Programmes Generalitat Valenciana, Spain; Göran Gustafssons Stiftelse, Sweden; The Royal Society and Leverhulme Trust, United Kingdom. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in Ref. ; A search optimized for new heavy particles decaying to two b-quarks and produced in association with additional b-quarks is reported. The sensitivity is improved by b-tagging at least one lower-pT jet in addition to the two highest-pT jets. The data used in this search correspond to an integrated luminosity of 103 fb-1 collected with a dedicated trijet trigger during the 2017 and 2018 s=13 TeV proton-proton collision runs with the ATLAS detector at the LHC. The search looks for resonant peaks in the b-tagged dijet invariant mass spectrum over a smoothly falling background. The background is estimated with an innovative data-driven method based on orthonormal functions. The observed b-tagged dijet invariant mass spectrum is compatible with the background-only hypothesis. Upper limits at 95% confidence level on a heavy vector-boson production cross section times branching ratio to a pair of b-quarks are derived. ; ANID ; BSF-NSF ; CEA-DRF ; Cantons of Bern and Geneva ; Czech Republic ; DNSRC IN2P3-CNRS ; EU-ESF ; GIF, Israel ; GenT Programmes Generalitat Valenciana, Spain ; IRFU ; La Caixa Banking Foundation ; MES of Russia ; MESTD ; MIZŠ ; MSMT ; MSSR ; Norwegian Financial Mechanism ; PROMETEO ; RGC ; VSC CR ; Wallenberg Foundation ; National Science Foundation ; U.S. Department of Energy ; Alexander von Humboldt-Stiftung ; Canarie ; H2020 Marie Skłodowska-Curie Actions ; Arizona-Nevada Academy of Science ; CERN ; Compute Canada ; Göran Gustafssons Stiftelser ; Natural Sciences and Engineering Research Council of Canada ; National Research Council Canada ; Canada Foundation for Innovation ; Science and Technology Facilities Council ; Leverhulme Trust ; Royal Society ; European Research Council ; European Cooperation in Science and Technology ; Australian Research Council ; Neurosurgical Research Foundation ; Singapore Eye Research Institute ; Helmholtz-Gemeinschaft ; Deutsche Forschungsgemeinschaft ; Agence Nationale de la Recherche ; Japan Society for the Promotion of Science ; Ministry of Education, Culture, Sports, Science and Technology ; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung ; Danmarks Grundforskningsfond ; Fundação de Amparo à Pesquisa do Estado de São Paulo ; National Natural Science Foundation of China ; Fundação para a Ciência e a Tecnologia ; Bundesministerium für Bildung und Forschung ; Chinese Academy of Sciences ; Austrian Science Fund ; Generalitat de Catalunya ; Agencia Nacional de Promoción Científica y Tecnológica ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek ; Bundesministerium für Wissenschaft, Forschung und Wirtschaft ; Conselho Nacional de Desenvolvimento Científico e Tecnológico ; Joint Institute for Nuclear Research ; Nella and Leon Benoziyo Center for Neurological Diseases, Weizmann Institute of Science ; Israel Science Foundation ; Instituto Nazionale di Fisica Nucleare ; Narodowe Centrum Nauki ; Javna Agencija za Raziskovalno Dejavnost RS ; Ministerstwo Edukacji i Nauki ; Ministry of Science and Technology, Taiwan ; Ministerio de Ciencia e Innovación ; Centre National pour la Recherche Scientifique et Technique ; Horizon 2020 ; British Columbia Knowledge Development Fund ; European Regional Development Fund ; Defence Science Institute ; Council on grants of the President of the Russian Federation ; National Research Center "Kurchatov Institute"