@article{OPUS4-15010,
  title     = {Search for heavy long-lived multi-charged particles in pp collisions at \(\sqrt {s}\) = 8 TeV using the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {8},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3534-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150100},
  pages     = {362},
  year      = {2015},
  abstract  = {A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2012 at \(\sqrt {s}\) = 8 TeV from pp collisions corresponding to an integrated luminosity of 20.3 fb\(^{-1}\) are examined. Particles producing anomalously high ionisation, consistent with long-lived massive particles with electric charges from |q| = 2e to |q| = 6e are searched for. No signal candidate events are observed, and 95 \% confidence level cross-section upper limits are interpreted as lower mass limits for a Drell-Yan production model. The mass limits range between 660 and 785 GeV.},
  language  = {en}
}
@article{OPUS4-15009,
  title     = {Search for direct pair production of a chargino and a neutralino decaying to the 125 GeV Higgs boson in \(\sqrt {s}\) = 8 TeV pp collisions with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {5},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3408-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150099},
  pages     = {208},
  year      = {2015},
  abstract  = {A search is presented for the direct pair production of a chargino and a neutralino pp → \(\tilde{χ}\)\(^{±}_{1}\)\(\tilde{χ}\)\(^{0}_{2}\), where the chargino decays to the lightest neutralino and the W boson, \(\tilde{χ}\)\(^{±}_{1}\)→\(\tilde{χ}\)\(^{0}_{1}\)(W\(^{±}\)→ℓ\(^{±}\)ν), while the neutralino decays to the lightest neutralino and the 125 GeV Higgs boson, \(\tilde{χ}\)\(^{0}_{2}\)→\(\tilde{χ}\)\(^{0}_{1}\)(h→bb/γγ/ℓ\(^{±}\)νqq). The final states considered for the search have large missing transverse momentum, an isolated electron or muon, and one of the following: either two jets identified as originating from bottom quarks, or two photons, or a second electron or muon with the same electric charge. The analysis is based on 20.3 fb\(^{-1}\) of \(\sqrt {s}\) = 8 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with the Standard Model expectations, and limits are set in the context of a simplified supersymmetric model.},
  language  = {en}
}
@article{OPUS4-15008,
  title     = {Search for dark matter in events with heavy quarks and missing transverse momentum in pp collisions with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {2},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3306-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150089},
  pages     = {92},
  year      = {2015},
  abstract  = {This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb\(^{-1}\) of pp collisions collected at \(\sqrt {s}\) = 8 TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing b-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter-nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a coloured mediator suitable to explain a possible signal of annihilating dark matter.},
  language  = {en}
}
@article{OPUS4-15007,
  title     = {Search for a new resonance decaying to a W or Z boson and a Higgs boson in the ℓℓ/ℓν/νν+b\(\overline{b}\) final states with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {6},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3474-x},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150075},
  pages     = {263},
  year      = {2015},
  abstract  = {A search for a new resonance decaying to a W or Z boson and a Higgs boson in the ℓℓ/ℓν/νν+b\(\overline{b}\) final states is performed using 20.3 fb\(^{-1}\) of pp collision data recorded at \(\sqrt {s}\) = 8 TeV with the ATLAS detector at the Large Hadron Collider. The search is conducted by examining the WH / ZH invariant mass distribution for a localized excess. No significant deviation from the Standard Model background prediction is observed. The results are interpreted in terms of constraints on the Minimal Walking Technicolor model and on a simplified approach based on a phenomenological Lagrangian of Heavy Vector Triplets.},
  language  = {en}
}
@article{OPUS4-15006,
  title     = {Search for W' → tb → qqbb decays in pp collisions at \(\sqrt {s}\) = 8 TeV with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {4},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3372-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150068},
  pages     = {165},
  year      = {2015},
  abstract  = {A search for a massive W′ gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in pp collisions at the LHC. The dataset was taken at a centre-of-mass energy of \(\sqrt {s}\) = 8 TeV and corresponds to 20.3 fb\(^{-1}\) of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass W′ bosons in the range 1.5-3.0  TeV. b-tagging is used to identify jets originating from b-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95 \% confidence level are set on the W′ → tb cross section times branching ratio ranging from 0.16 pb to 0.33 pb for left-handed W′ bosons, and ranging from 0.10 pb to 0.21 pb for W′ bosons with purely right-handed couplings. Upper limits at 95 \% confidence level are set on the W′-boson coupling to tb as a function of the W′ mass using an effective field theory approach, which is independent of details of particular models predicting a W′ boson.},
  language  = {en}
}
@article{OPUS4-15003,
  title     = {Performance of the ATLAS muon trigger in pp collisions at \(\sqrt {s}\)= 8 TeV},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {3},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3325-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150032},
  pages     = {120},
  year      = {2015},
  abstract  = {The performance of the ATLAS muon trigger system is evaluated with proton-proton collision data collected in 2012 at the Large Hadron Collider at a centre-of-mass energy of 8 TeV. It is primarily evaluated using events containing a pair of muons from the decay of Z bosons. The efficiency of the single-muon trigger is measured for muons with transverse momentum 25 < p\(_{T}\) < 100GeV, with a statistical uncertainty of less than 0.01 \% and a systematic uncertainty of 0.6 \%. The pT range for efficiency determination is extended by using muons from decays of J/ψ mesons, W bosons, and top quarks. The muon trigger shows highly uniform and stable performance. The performance is compared to the prediction of a detailed simulation.},
  language  = {en}
}
@article{OPUS4-14997,
  title     = {Observation and measurements of the production of prompt and non-prompt J/ψ mesons in association with a Z boson in pp collisions at \(\sqrt {s}\)=8 TeV with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {5},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3406-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149970},
  pages     = {229},
  year      = {2015},
  abstract  = {The production of a Z boson in association with a J/ψ meson in proton-proton collisions probes the production mechanisms of quarkonium and heavy flavour in association with vector bosons, and allows studies of multiple parton scattering. Using 20.3fb\(^{-1}\) of data collected with the ATLAS experiment at the LHC in pp collisions at \(\sqrt {s}\) = 8 TeV, the first measurement of associated Z+J/ψ production is presented for both prompt and non-prompt J/ψ production, with both signatures having a significance in excess of 5σ. The inclusive production cross-sections for Z boson production (analysed in μ\(^{+}\)μ\(^{-}\) or e\(^{+}\)e\(^{-}\) decay modes) in association with prompt and non-prompt J/ψ(→μ\(^{+}\)μ\(^{-}\)) are measured relative to the inclusive production rate of Z bosons in the same fiducial volume to be (36.8±6.7±2.5)×10\(^{-7}\) and (65.8±9.2±4.2)×10\(^{-7}\) respectively. Normalised differential production cross-section ratios are also determined as a function of the J/ψ transverse momentum. The fraction of signal events arising from single and double parton scattering is estimated, and a lower limit of 5.3 (3.7)mb at 68 (95)\% confidence level is placed on the effective cross-section regulating double parton interactions.},
  language  = {en}
}
@article{OPUS4-14992,
  title     = {Measurements of the W production cross sections in association with jets with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {2},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3262-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149925},
  pages     = {82},
  year      = {2015},
  abstract  = {This paper presents cross sections for the production of a W boson in association with jets, measured in proton-proton collisions at \(\sqrt {s}\) = 7 TeV with the ATLAS experiment at the large hadron collider. With an integrated luminosity of 4.6 fb\(^{-1}\), this data set allows for an exploration of a large kinematic range, including jet production up to a transverse momentum of 1 TeV and multiplicities up to seven associated jets. The production cross sections for W bosons are measured in both the electron and muon decay channels. Differential cross sections for many observables are also presented including measurements of the jet observables such as the rapidities and the transverse momenta as well as measurements of event observables such as the scalar sums of the transverse momenta of the jets. The measurements are compared to numerous QCD predictions including next-to-leading-order perturbative calculations, resummation calculations and Monte Carlo generators.},
  language  = {en}
}
@article{OPUS4-14991,
  title     = {Measurement of three-jet production cross-sections in pp collisions at 7 TeV centre-of-mass energy using the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {5},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3363-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149918},
  pages     = {228},
  year      = {2015},
  abstract  = {Double-differential three-jet production cross-sections are measured in proton-proton collisions at a centre-of-mass energy of \(\sqrt {s}\) = 7 TeV using the ATLAS detector at the large hadron collider. The measurements are presented as a function of the three-jet mass (m\(_{jjj}\)), in bins of the sum of the absolute rapidity separations between the three leading jets (|Y\(^{*}\)|). Invariant masses extending up to 5 TeV are reached for 8 < |Y\(^{*}\)| < 10. These measurements use a sample of data recorded using the ATLAS detector in 2011, which corresponds to an integrated luminosity of 4.51 fb\(^{-1}\). Jets are identified using the anti-k\(_{t}\) algorithm with two different jet radius parameters, R = 0.4 and R = 0.6. The dominant uncertainty in these measurements comes from the jet energy scale. Next-to-leading-order QCD calculations corrected to account for non-perturbative effects are compared to the measurements. Good agreement is found between the data and the theoretical predictions based on most of the available sets of parton distribution functions, over the full kinematic range, covering almost seven orders of magnitude in the measured cross-section values.},
  language  = {en}
}
@article{OPUS4-14990,
  title     = {Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at \(\sqrt {s}\)=7TeV},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {4},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3373-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149905},
  pages     = {158},
  year      = {2015},
  abstract  = {The mass of the top quark is measured in a data set corresponding to 4.6  fb\(^{-1}\) of proton-proton collisions with centre-of-mass energy \(\sqrt {s}\)=7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top-antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified b-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jet to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the W boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of m\(_{t}\)= 175.1 ± 1.4 (stat.) ± 1.2 (syst.) GeV.},
  language  = {en}
}