@article{OPUS4-12959,
  title     = {Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb\(^{-1}\) of √s=7TeV proton-proton collisions},
  series = {The Journal of High Energy Physics},
  volume    = {07},
  journal   = {The Journal of High Energy Physics},
  number    = {167},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP07(2012)167},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129591},
  year      = {2012},
  abstract  = {Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb\(^{-1}\) of pp collision data at √s=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95\% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV.},
  language  = {en}
}
@article{OPUS4-12955,
  title     = {A search for \(t\overline t\) resonances in lepton+jets events with highly boosted top quarks collected in pp collisions at √s=7 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {09},
  journal   = {Journal of High Energy Physics},
  number    = {41},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP09(2012)041},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129555},
  year      = {2012},
  abstract  = {A search for resonant production of high-mass top-quark pairs is performed on 2.05 fb\(^{-1}\) of proton-proton collisions at √s=7 TeV collected in 2011 with the ATLAS experiment at the Large Hadron Collider. This analysis of the lepton+jets final state is specifically designed for the particular topology that arises from the decay of highly boosted top quarks. The observed \(t\overline t\) invariant mass spectrum is found to be compatible with the Standard Model prediction and 95\% credibility level upper limits are derived on the \(t\overline t\) production rate through new massive states. An upper limit of 0.7 pb is set on the production cross section times branching fraction of a narrow 1 TeV resonance. A Kaluza-Klein gluon with a mass smaller than 1.5 TeV is excluded.},
  language  = {en}
}
@article{OPUS4-12917,
  title     = {Search for R-parity-violating supersymmetry in events with four or more leptons in √s=7 TeV pp collisions with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {12},
  journal   = {Journal of High Energy Physics},
  number    = {124},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP12(2012)124},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129179},
  year      = {2012},
  abstract  = {A search for new phenomena in final states with four or more leptons (electrons or muons) is presented. The analysis is based on 4.7 fb\(^{-1}\) of √s=7 TeV proton-proton collisions delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in two signal regions: one that requires moderate values of missing transverse momentum and another that requires large effective mass. The results are interpreted in a simplified model of R-parity-violating supersymmetry in which a 95\% CL exclusion region is set for charged wino masses up to 540 GeV. In an R-parity-violating MSUGRA/CMSSM model, values of m 1/2 up to 820 GeV are excluded for 10 < tan β < 40.},
  language  = {en}
}
@article{OPUS4-12916,
  title     = {Search for charged Higgs bosons decaying via H\(^±\) → τν in \(t\overline t\) events using pp collision data at √s=7 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {06},
  journal   = {Journal of High Energy Physics},
  number    = {39},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP06(2012)039},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129163},
  year      = {2012},
  abstract  = {The results of a search for charged Higgs bosons are presented. The analysis is based on 4.6fb\(^{-1}\) of proton-proton collision data at √s=7TeV collected by the ATLAS experiment at the Large Hadron Collider, using top quark pair events with a τ lepton in the final state. The data are consistent with the expected background from Standard Model processes. Assuming that the branching ratio of the charged Higgs boson to a τ lepton and a neutrino is 100 \%, this leads to upper limits on the branching ratio of top quark decays to a b quark and a charged Higgs boson between 5\% and 1\% for charged Higgs boson masses ranging from 90 GeV to 160 GeV, respectively. In the context of the m\(^{max}_h\) scenario of the MSSM, tan β above 12-26, as well as between 1 and 2-6, can be excluded for charged Higgs boson masses between 90 GeV and 150 GeV.},
  language  = {en}
}
@article{OPUS4-12897,
  title     = {Jet mass and substructure of inclusive jets in √s=7 TeV pp collisions with the ATLAS experiment},
  series = {Journal of High Energy Physics},
  volume    = {05},
  journal   = {Journal of High Energy Physics},
  number    = {128},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP05(2012)128},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128970},
  year      = {2012},
  abstract  = {Recent studies have highlighted the potential of jet substructure techniques to identify the hadronic decays of boosted heavy particles. These studies all rely upon the assumption that the internal substructure of jets generated by QCD radiation is well understood. In this article, this assumption is tested on an inclusive sample of jets recorded with the ATLAS detector in 2010, which corresponds to 35 pb\(^{-1}\) of pp collisions delivered by the LHC at √s=7TeV. In a subsample of events with single pp collisions, measurements corrected for detector efficiency and resolution are presented with full systematic uncertainties. Jet invariant mass, k\(_t\) splitting scales and N-subjettiness variables are presented for anti-k\(_t\) R = 1.0 jets and Cambridge-Aachen R = 1.2 jets. Jet invariant-mass spectra for Cambridge-Aachen R = 1.2 jets after a splitting and filtering procedure are also presented. Leading-order parton-shower Monte Carlo predictions for these variables are found to be broadly in agreement with data. The dependence of mean jet mass on additional pp interactions is also explored.},
  language  = {en}
}
@article{OPUS4-12896,
  title     = {Search for same-sign top-quark production and fourth-generation down-type quarks in pp collisions at √s=7 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {04},
  journal   = {Journal of High Energy Physics},
  number    = {69},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP04(2012)069},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128960},
  year      = {2012},
  abstract  = {A search is presented for same-sign top-quark production and down-type heavy quarks of charge -1/3 in events with two isolated leptons (e or μ) that have the same electric charge, at least two jets and large missing transverse momentum. The data are selected from pp collisions at √s=7TeV recorded by the ATLAS detector and correspond to an integrated luminosity of 1.04 fb\(^{-1}\). The observed data are consistent with expectations from Standard Model processes. Upper limits are set at 95 \% confidence level on the cross section of new sources of same-sign top-quark pair production of 1.4-2.0 pb depending on the assumed mediator mass. Upper limits are also set on the pair-production cross-section for new heavy down-type quarks; a lower limit of 450 GeV is set at 95 \% confidence level on the mass of heavy down-type quarks under the assumption that they decay 100 \% of the time to W t.},
  language  = {en}
}
@article{OPUS4-12892,
  title     = {Measurement of the cross section for top-quark pair production in pp collisions at √s=7TeV with the ATLAS detector using final states with two high-p\(_T\) leptons},
  series = {Journal of High Energy Physics},
  volume    = {5},
  journal   = {Journal of High Energy Physics},
  number    = {59},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP05(2012)059},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128924},
  year      = {2012},
  abstract  = {A measurement is reported of the production cross section of top-quark pairs (\(t\overline t\)) in proton-proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the LHC. Candidate events have a signature consistent with containing two isolated leptons, large missing transverse momentum, and at least two jets. Using a data sample corresponding to an integrated luminosity of 0.70 fb\(^{-1}\), a \(t\overline t\) production cross section σ\(_{t\overline t}\)=176±5(stat.)\(^{+14}_{-11}\)(syst.)±8(lum.) pb is measured for an assumed top-quark mass of m\(_t\)  = 172.5 GeV. This measurement is in good agreement with Standard Model predictions.},
  language  = {en}
}
@article{OPUS4-12813,
  title     = {Search for pair production of massive particles decaying into three quarks with the ATLAS detector in √s=7TeV pp collisions at the LHC},
  series = {Journal of High Energy Physics},
  volume    = {12},
  journal   = {Journal of High Energy Physics},
  number    = {86},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP12(2012)086},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128133},
  year      = {2012},
  abstract  = {A search is conducted for hadronic three-body decays of a new massive coloured particle in √s=7TeV pp collisions at the LHC using an integrated luminosity of 4.6 fb\(^{-1}\) collected by the ATLAS detector. Supersymmetric gluino pair production in the context of a model with R-parity violation is used as a benchmark scenario. The analysis is divided into two search channels, each optimised separately for their sensitivity to high-mass and low-mass gluino production. The first search channel uses a stringent selection on the transverse momentum of the six leading jets and is performed as a counting experiment. The second search channel focuses on low-mass gluinos produced with a large boost. Large-radius jets are selected and the invariant mass of each of the two leading jets is used as a discriminant between the signal and the background. The results are found to be consistent with Standard Model expectations and limits are set on the allowed gluino mass.},
  language  = {en}
}
@article{OPUS4-12812,
  title     = {Time-dependent angular analysis of the decay B\(^0_s\)→J/ψϕ and extraction of ΔΓ\(_s\) and the CP-violating weak phase ϕ\(_s\) by ATLAS},
  series = {Journal of High Energy Physics},
  volume    = {12},
  journal   = {Journal of High Energy Physics},
  number    = {072},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP12(2012)072},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128125},
  year      = {2012},
  abstract  = {A measurement of B\(^0_s\)→J/ψϕ decay parameters, including the CP -violating weak phase ϕ\(_s\) and the decay width difference ΔΓ\(_s\) is reported, using 4.9 fb\(^{-1}\) of integrated luminosity collected in 2011 by the ATLAS detector from LHC pp collisions at a centre-of-mass energy √s=7 TeV. The mean decay width Γ\(_s\) and the transversity amplitudes |A\(_0\)(0)|\(^2\) and |A\(_∥\)(0)|\(^2\) are also measured. The values reported for these parameters are: ϕ\(_s\)=0.22±0.41 (stat.)±0.10 (syst.) rad ΔΓ\(_s\)=0.053±0.021 (stat.)±0.010 (syst.)ps\(^{-1}\) Γ\(_s\)=0.677±0.007 (stat.)±0.004 (syst.) ps\(^{-1}\) |A\(_0\)(0)|\(^2\)=0.528±0.006 (stat.)±0.009 (syst.) |A\(_∥\)(0)|\(^2\)=0.220±0.008 (stat.)±0.007 (syst.) where the values quoted for ϕ\(_s\) and ΔΓ\(_s\) correspond to the solution compatible with the external measurements to which the strong phase δ\(_⊥\) is constrained and where ΔΓ\(_s\) is constrained to be positive. The fraction of S-wave KK or f\(_0\) contamination through the decays B\(^0_s\)→J/ψK\(^+\)K\(^-\)(f\(_0\)) is measured as well and is found to be consistent with zero. Results for ϕ\(_s\) and ΔΓ\(_s\) are also presented as 68\%, 90\% and 95\% likelihood contours, which show agreement with Standard Model expectations.},
  language  = {en}
}
@article{OPUS4-12799,
  title     = {Measurements of the pseudorapidity dependence of the total transverse energy in proton-proton collisions at √s=7 TeV with ATLAS},
  series = {Journal of High Energy Physics},
  volume    = {11},
  journal   = {Journal of High Energy Physics},
  number    = {033},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP11(2012)033},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127998},
  year      = {2012},
  abstract  = {This paper describes measurements of the sum of the transverse energy of particles as a function of particle pseudorapidity, η, in proton-proton collisions at a centre-of-mass energy, √s=7 TeV using the ATLAS detector at the Large Hadron Collider. The measurements are performed in the region |η| < 4.8 for two event classes: those requiring the presence of particles with a low transverse momentum and those requiring particles with a significant transverse momentum. In the second dataset measurements are made in the region transverse to the hard scatter. The distributions are compared to the predictions of various Monte Carlo event generators, which generally tend to underestimate the amount of transverse energy at high |η|.},
  language  = {en}
}