@article{OPUS4-17275,
  title     = {Searches for the \(Z\)γ decay mode of the Higgs boson and for new high-mass resonances in \({pp}\) collisions at \(\sqrt{s}\) = 13 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {10},
  organization    = {The ATLAS Collaboration},
  doi       = {https://doi.org/10.1007/JHEP10(2017)112},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172751},
  year      = {2017},
  abstract  = {This article presents searches for the \({Zγ}\) decay of the Higgs boson and for narrow high-mass resonances decaying to \(Z\)γ, exploiting \(Z\) boson decays to pairs of electrons or muons. The data analysis uses 36.1 fb\(^{-1}\) of \({pp}\) collisions at \(\sqrt{s}=13\) recorded by the ATLAS detector at the CERN Large Hadron Collider. The data are found to be consistent with the expected Standard Model background. The observed (expected — assuming Standard Model \({pp} → H → {Z}γ\) production and decay) upper limit on the production cross section times the branching ratio for \({pp} → H → {Z}γ\) is 6.6. (5.2) times the Standard Model prediction at the 95\% confidence level for a Higgs boson mass of 125.09 GeV. In addition, upper limits are set on the production cross section times the branching ratio as a function of the mass of a narrow resonance between 250 GeV and 2.4 TeV, assuming spin-0 resonances produced via gluon-gluon fusion, and spin-2 resonances produced via gluon-gluon or quark-antiquark initial states. For high-mass spin-0 resonances, the observed (expected) limits vary between 88 fb (61 fb) and 2.8 fb (2.7 fb) for the mass range from 250 GeV to 2.4 TeV at the 95\% confidence level.},
  language  = {en}
}
@article{OPUS4-27753,
  title     = {Search for squarks and gluinos in final states with same-sign leptons and jets using 139 fb\(^{-1}\) of data collected with the ATLAS detector},
  series = {Journal of High Energy Physics},
  journal   = {Journal of High Energy Physics},
  number    = {6},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP06(2020)046},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-277538},
  pages     = {46},
  year      = {2020},
  abstract  = {A search for supersymmetric partners of gluons and quarks is presented, involving signatures with jets and either two isolated leptons (electrons or muons) with the same electric charge, or at least three isolated leptons. A data sample of proton-proton collisions at root s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018, corresponding to a total integrated luminosity of 139 fb(-1), is used for the search. No significant excess over the Standard Model expectation is observed. The results are interpreted in simplified supersymmetric models featuring both R-parity conservation and R-parity violation, raising the exclusion limits beyond those of previous ATLAS searches to 1600 GeV for gluino masses and 750 GeV for bottom and top squark masses in these scenarios.},
  language  = {en}
}
@article{OPUS4-17360,
  title     = {Measurements of charge and CP asymmetries in \(b\)-hadron decays using top-quark events collected by the ATLAS detector in \(pp\) collisions at \(\sqrt{s}\) = 8 TeV},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {02},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP02(2017)071},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173603},
  year      = {2017},
  abstract  = {Same- and opposite-sign charge asymmetries are measured in lepton+jets \({t\overline{t}}\) events in which a \(b\)-hadron decays semileptonically to a soft muon, using data corresponding to an integrated luminosity of 20.3 fb\(^{-1}\) from proton-proton collisions at a centre-of-mass energy of \(\sqrt{s}\) = 8 TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. The charge asymmetries are based on the charge of the lepton from the top-quark decay and the charge of the soft muon from the semileptonic decay of a \(b\)-hadron and are measured in a fiducial region corresponding to the experimental acceptance. Four CP asymmetries (one mixing and three direct) are measured and are found to be compatible with zero and consistent with the Standard Model.},
  language  = {en}
}
@article{OPUS4-17241,
  title     = {Measurement of \(b\)-hadron pair production with the ATLAS detector in proton-proton collisions at \(\sqrt{s}=8\) TeV},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {11},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP11(2017)062},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172414},
  year      = {2017},
  abstract  = {A measurement of \(b\)-hadron pair production is presented, based on a data set corresponding to an integrated luminosity of 11.4 fb\(^{-1}\) of proton-proton collisions recorded at \(\sqrt{s}=8\) TeV with the ATLAS detector at the LHC. Events are selected in which a \(b\)-hadron is reconstructed in a decay channel containing \(J/ψ → μμ\), and a second \(b\)-hadron is reconstructed in a decay channel containing a muon. Results are presented in a fiducial volume defined by kinematic requirements on three muons based on those used in the analysis. The fiducial cross section is measured to be 17.7 ± 0.1(stat.) ± 2.0(syst.) nb. A number of normalised differential cross sections are also measured, and compared to predictions from the PHYTHIA8, HERWIG++, MADGRAPH5_AMC@NLO+PYTHIA8 and SHERPA event generators, providing new constraints on heavy flavour production.},
  language  = {en}
}
@article{OPUS4-17221,
  title     = {Evidence for the \(H\) → \({b\overline{b}}\) decay with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {24},
  journal   = {Journal of High Energy Physics},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP12(2017)024},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172216},
  year      = {2017},
  abstract  = {A search for the decay of the Standard Model Higgs boson into a \({b\overline{b}}\) pair when produced in association with a \(W\) or \(Z\) boson is performed with the ATLAS detector. The analysed data, corresponding to an integrated luminosity of 36.1 fb\(^{-1}\), were collected in proton-proton collisions in Run 2 of the Large Hadron Collider at a centre-of-mass energy of 13 TeV. Final states containing zero, one and two charged leptons (electrons or muons) are considered, targeting the decays \(Z\) → \({νν}\), \(W\) → \({ℓν}\) and \(Z\) → \({ℓℓ}\). For a Higgs boson mass of 125 GeV, an excess of events over the expected background from other Standard Model processes is found with an observed significance of 3.5 standard deviations, compared to an expectation of 3.0 standard deviations. This excess provides evidence for the Higgs boson decay into b-quarks and for its production in association with a vector boson. The combination of this result with that of the Run 1 analysis yields a ratio of the measured signal events to the Standard Model expectation equal to 0.90 ± 0.18(stat.)\(^{+0.21}_{-0.19}\)(syst.). Assuming the Standard Model production cross-section, the results are consistent with the value of the Yukawa coupling to \(b\)-quarks in the Standard Model.},
  language  = {en}
}
@article{OPUS4-17323,
  title     = {Probing the \(W tb\) vertex structure in \(t\)-channel single-top-quark production and decay in \(pp\) collisions at \(\sqrt{s}\) = 8 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {04},
  organization    = {The ATLAS Collaboration},
  doi       = {https://doi.org/10.1007/JHEP04(2017)124},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173234},
  year      = {2017},
  abstract  = {To probe the \(W tb\) vertex structure, top-quark and \(W\)-boson polarisation observables are measured from \(t\)-channel single-top-quark events produced in proton-proton collisions at a centre-of-mass energy of 8 TeV. The dataset corresponds to an integrated luminosity of 20.2 fb\(^{-1}\), recorded with the ATLAS detector at the LHC. Selected events contain one isolated electron or muon, large missing transverse momentum and exactly two jets, with one of them identified as likely to contain a \(b\)-hadron. Stringent selection requirements are applied to discriminate \(t\)-channel single-top-quark events from background. The polarisation observables are extracted from asymmetries in angular distributions measured with respect to spin quantisation axes appropriately chosen for the top quark and the \(W\) boson. The asymmetry measurements are performed at parton level by correcting the observed angular distributions for detector effects and hadronisation after subtracting the background contributions. The measured top-quark and \(W\)-boson polarisation values are in agreement with the Standard Model predictions. Limits on the imaginary part of the anomalous coupling \(g_R\) are also set from model independent measurements.},
  language  = {en}
}
@article{OPUS4-17354,
  title     = {Measurements of top-quark pair to \(Z\)-boson cross-section ratios at \(\sqrt{s}\) \(=13 , 8, 7\) TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {02},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP02(2017)117},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173544},
  year      = {2017},
  abstract  = {Ratios of top-quark pair to \(Z\)-boson cross sections measured from proton-proton collisions at the LHC centre-of-mass energies of \(\sqrt{s}\) = 13 TeV, 8 TeV, and 7 TeV are presented by the ATLAS Collaboration. Single ratios, at a given \(\sqrt{s}\) for the two processes and at different \(\sqrt{s}\) for each process, as well as double ratios of the two processes at different \(\sqrt{s}\), are evaluated. The ratios are constructed using previously published ATLAS measurements of the \({t\overline{t}}\) and \(Z\)-boson production cross sections, corrected to a common phase space where required, and a new analysis of \(Z\) → ℓ\(^+\)ℓ\(^-\) where ℓ = \(e, µ\) at \(\sqrt{s}\) = 13 TeV performed with data collected in 2015 with an integrated luminosity of 3.2 fb\(^-1\). Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the \(Z\) → \(e\)\(^+\)\(e\)\(^-\) and the \(Z\) → \(µ\)\(^+\)\(µ\)\(^-\) channels for each \(\sqrt{s}\) value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-\(x\) values near 0.1 and the light-quark sea for \(x\) < 0.02.},
  language  = {en}
}
@article{OPUS4-17361,
  title     = {Measurement of the \(ZZ\) production cross section in proton-proton collisions at \(\sqrt{s}\) = 8 TeV using the \(ZZ\) → \(ℓ^-ℓ^+ℓ^{′-}ℓ^{′+}\) and \(ZZ\) → \(ℓ^-ℓ^+{ν\overline{ν}}\) decay channels with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {99},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1007/JHEP01(2017)099},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173616},
  year      = {2017},
  abstract  = {A measurement of the \(ZZ\) production cross section in the \(ℓ^-ℓ^+ℓ^{′-}ℓ^{′+}\) and \(ℓ^-ℓ^+{ν\overline{ν}}\) channels (ℓ = e, µ) in proton-proton collisions at \(\sqrt{s}\) = 8TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb\(^{-1}\) collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for \(ZZ\) → \(ℓ^-ℓ^+ℓ^{′-}ℓ^{′+}\) and \(ZZ\) → \(ℓ^-ℓ^+{ν\overline{ν}}\) are measured in selected phase-space regions. The total cross section for \(ZZ\) events produced with both \(Z\) bosons in the mass range 66 to 116GeV is measured from the combination of the two channels to be 7.3 ± 0.4(stat) ± 0.3 (syst)\(^{-0.2}_{-0.1}\) (lumi) pb, which is consistent with the Standard Model prediction of 6.6\(^{+0.7}_{-0.6}\) pb. The differential cross sections in bins of various kinematic variables are presented. The differential event yield as a function of the transverse momentum of the leading \(Z\) boson is used to set limits on anomalous neutral triple gauge boson couplings in \(ZZ\) production.},
  language  = {en}
}
@article{OPUS4-17366,
  title     = {Measurement of the \({t\overline{t}}Z\) and \({t\overline{t}}W\) production cross sections in multilepton final states using 3.2 fb\(^{-1}\) of \(pp\) collisions at \(\sqrt{s}\) = 13 TeV with the ATLAS detector},
  series = {European Physical Journal C},
  volume    = {77},
  journal   = {European Physical Journal C},
  number    = {40},
  organization    = {The ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-016-4574-y},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173662},
  year      = {2017},
  abstract  = {A measurement of the \({t\overline{t}}Z\) and \({t\overline{t}}W\) production cross sections in final states with either two same-charge muons, or three or four leptons (electrons or muons) is presented. The analysis uses a data sample of proton-proton collisions at \(\sqrt{s}\) = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015, corresponding to a total integrated luminosity of 3.2 fb\(^{-1}\). The inclusive cross sections are extracted using likelihood fits to signal and control regions, resulting in \(\sigma_{{t\overline{t}}Z}\) = 0.9 ± 0.3 pb and \(\sigma_{{t\overline{t}}W}\) = 1.5 ± 0.8 pb, in agreement with the Standard Model predictions.},
  language  = {en}
}
@article{OPUS4-17322,
  title     = {Studies of \(Zγ\) production in association with a high-mass dijet system in \(pp\) collisions at \(\sqrt{s}\) = 8 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {2017},
  journal   = {Journal of High Energy Physics},
  number    = {07},
  organization    = {The ATLAS Collaboration},
  doi       = {https://doi.org/10.1007/JHEP07(2017)107},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173229},
  year      = {2017},
  abstract  = {The production of a \(Z\) boson and a photon in association with a high-mass dijet system is studied using 20.2 fb\(^{-1}\) of proton-proton collision data at a centre-of-mass energy of \(\sqrt{s}\) = 8 TeV recorded with the ATLAS detector in 2012 at the Large Hadron Collider. Final states with a photon and a Z boson decaying into a pair of either electrons, muons, or neutrinos are analysed. Electroweak and total \(pp\) → \(Zγjj\) cross-sections are extracted in two fiducial regions with different sensitivities to electroweak production processes. Quartic couplings of vector bosons are studied in regions of phase space with an enhanced contribution from pure electroweak production, sensitive to vector-boson scattering processes \(V V → Zγ\). No deviations from Standard Model predictions are observed and constraints are placed on anomalous couplings parameterized by higher-dimensional operators using effective field theory.},
  language  = {en}
}