@article{OPUS4-22595,
  title     = {Searches for heavy \({ZZ}\) and \({ZW}\) resonances in the \({llqq}\) and \({vvqq}\) final states in \({pp}\) collisions at root s=13 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {9},
  journal   = {Journal of High Energy Physics},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP03(2018)009},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225951},
  pages     = {1-52},
  year      = {2018},
  abstract  = {This paper reports searches for heavy resonances decaying into ZZ or ZW using data from proton-proton collisions at a centre-of-mass energy of root s - 13 TeV. The data, corresponding to an integrated luminosity of 36.1 fb(-1), were recorded with the ATLAS detector in 2015 and 2016 at the Large Hadron Collider. The searches are performed in final states in which one Z boson decays into either a pair of light charged leptons (electrons and muons) or a pair of neutrinos, and the associated W boson or the other Z boson decays hadronically. No evidence of the production of heavy resonances is observed. Upper bounds on the production cross sections of heavy resonances times their decay branching ratios to ZZ or ZW are derived in the mass range 300-5000 GeV within the context of Standard Model extensions with additional Higgs bosons, a heavy vector triplet or warped extra dimensions. Production through gluon-gluon fusion, Drell-Yan or vector-boson fusion are considered, depending on the assumed model.},
  language  = {en}
}
@article{OPUS4-22542,
  title     = {Search for heavy \({ZZ}\) resonances in the l\(^+\)l\(^-\)l\(^+\)l\(^-\) and l\(^+\)l\(^-\) nu(nu)over-bar final states using proton-proton collisions at root s=13 TeV with the ATLAS detector},
  series = {The European Physical Journal C},
  volume    = {78},
  journal   = {The European Physical Journal C},
  number    = {293},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-018-5686-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225421},
  pages     = {1-34},
  year      = {2018},
  abstract  = {A search for heavy resonances decaying into a pair of Z bosons leading to l(+) l(-) l(+) l(-) and l(+) l(-) nu(nu) over bar final states, where l stands for either an electron or a muon, is presented. The search uses proton-proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 36.1 fb(-1) collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 and 2000 GeV. The results are interpreted as upper limits on the production cross section of a spin-0 or spin-2 resonance. The upper limits for the spin-0 resonance are translated to exclusion contours in the context of Type-I and Type-II two-Higgs-doublet models, while those for the spin-2 resonance are used to constrain the Randall-Sundrum model with an extra dimension giving rise to spin-2 graviton excitations.},
  language  = {en}
}
@article{OPUS4-22613,
  title     = {Search for pair production of up-type vector-like quarks and for four-top-quark events in final states with multiple \(b\)-jets with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {89},
  journal   = {Journal of High Energy Physics},
  number    = {7},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP07(2018)089},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226131},
  pages     = {1-67},
  year      = {2018},
  abstract  = {A search for pair production of up-type vector-like quarks (T) with a significant branching ratio into a top quark and either a Standard Model Higgs boson or a Z boson is presented. The same analysis is also used to search for four-top-quark production in several new physics scenarios. The search is based on a dataset of pp collisions at root s = 13TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider and corresponds to an integrated luminosity of 36.1 fb(-1). Data are analysed in the lepton+jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets, as well as the jets+E-T(miss) final state, characterised by multiple jets and large missing transverse momentum. The search exploits the high multiplicity of jets identified as originating from b-quarks, and the presence of boosted, hadronically decaying top quarks and Higgs bosons reconstructed as large-radius jets, characteristic of signal events. No significant excess above the Standard Model expectation is observed, and 95\% CL upper limits are set on the production cross sections for the different signal processes considered. These cross-section limits are used to derive lower limits on the mass of a vector-like T quark under several branching ratio hypotheses assuming contributions from T -> Wb, Zt, Ht decays. The 95\% CL observed lower limits on the T quark mass range between 0.99TeV and 1.43TeV for all possible values of the branching ratios into the three decay modes considered, significantly extending the reach beyond that of previous searches. Additionally, upper limits on anomalous four-top-quark production are set in the context of an effective field theory model, as well as in an universal extra dimensions model.},
  language  = {en}
}
@article{OPUS4-22687,
  title     = {Search for electroweak diboson production in association with a high-mass dijet system in semileptonic final states in \(pp\) collisions at √\(s\) =13 TeV with the ATLAS detector},
  series = {Physical Review D},
  volume    = {100},
  journal   = {Physical Review D},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1103/PhysRevD.100.032007},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226877},
  pages     = {36},
  year      = {2019},
  abstract  = {This paper reports on a search for electroweak diboson (WW/WZ/ZZ) production in association with a high-mass dijet system, using data from proton-proton collisions at a center-of-mass energy of N root s = 13 TeV. The data, corresponding to an integrated luminosity of 35.5 fb(-1), were recorded with the ATLAS detector in 2015 and 2016 at the Large Hadron Collider. The search is performed in final states in which one boson decays leptonically, and the other boson decays hadronically. The hadronically decaying W/Z boson is reconstructed as either two small-radius jets or one large-radius jet using jet substructure techniques. The electroweak production of WW/WZ/ZZ in association with two jets is measured with an observed (expected) significance of 2.7 (2.5) standard deviations, and the fiducial cross section is measured to be 45.1 +/- 8.6(stat.)(-14.6)(+15.9)(syst.) fb.},
  language  = {en}
}