@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{OPUS4-12896,
  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{OPUS4-12917,
  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{OPUS4-12813,
  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{OPUS4-12797,
  title     = {Search for high-mass resonances decaying to dilepton final states in pp collisions at √s=7 TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {11},
  journal   = {Journal of High Energy Physics},
  number    = {138},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP11(2012)138},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127974},
  year      = {2012},
  abstract  = {The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to an electron-positron pair or a muon-antimuon pair. The search is sensitive to heavy neutral Z′ gauge bosons, Randall-Sundrum gravitons, Z* bosons, techni-mesons, Kaluza-Klein Z/γ bosons, and bosons predicted by Torsion models. Results are presented based on an analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.9 fb\(^{-1}\) in the e\(^+\)e\(^-\) channel and 5.0 fb\(^{-1}\) in the μ\(^+\)μ\(^-\)channel. A Z′ boson with Standard Model-like couplings is excluded at 95 \% confidence level for masses below 2.22 TeV. A Randall-Sundrum graviton with coupling k/\(\overline M_{Pl}\)=0.1 is excluded at 95 \% confidence level for masses below 2.16 TeV. Limits on the other models are also presented, including Technicolor and Minimal Z′ Models.},
  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{OPUS4-12798,
  title     = {Search for anomalous production of prompt like-sign lepton pairs at √s=7TeV with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {12},
  journal   = {Journal of High Energy Physics},
  number    = {7},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP12(2012)007},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127983},
  year      = {2012},
  abstract  = {An inclusive search for anomalous production of two prompt, isolated leptons with the same electric charge is presented. The search is performed in a data sample corresponding to 4.7 fb\(^{-1}\) of integrated luminosity collected in 2011 at √s=7TeV with the ATLAS detector at the LHC. Pairs of leptons (e\(^{±}\)e\(^{±}\), e\(^{±}\)μ\(^{±}\), and μ\(^{±}\)μ\(^{±}\)) with large transverse momentum are selected, and the dilepton invariant mass distribution is examined for any deviation from the Standard Model expectation. No excess is found, and upper limits on the production cross section of like-sign lepton pairs from physics processes beyond the Standard Model are placed as a function of the dilepton invariant mass within a fiducial region close to the experimental selection criteria. The 95\% confidence level upper limits on the cross section of anomalous e\(^{±}\)e\(^{±}\), e\(^{±}\)μ\(^{±}\), or μ\(^{±}\)μ\(^{±}\) production range between 1.7 fb and 64 fb depending on the dilepton mass and flavour combination.},
  language  = {en}
}
@article{OPUS4-12751,
  title     = {Search for a heavy top-quark partner in final states with two leptons with the ATLAS detector at the LHC},
  series = {Journal of High Energy Physics},
  volume    = {11},
  journal   = {Journal of High Energy Physics},
  number    = {094},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP11(2012)094},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127511},
  year      = {2012},
  abstract  = {The results of a search for direct pair production of heavy top-quark partners in 4.7 fb\(^{-1}\) of integrated luminosity from pp collisions at √s=7 TeV collected by the ATLAS detector at the LHC are reported. Heavy top-quark partners decaying into a top quark and a neutral non-interacting particle are searched for in events with two leptons in the final state. No excess above the Standard Model expectation is observed. Limits are placed on the mass of a supersymmetric scalar top and of a spin-1/2 top-quark partner. A spin-1/2 top-quark partner with a mass between 300 GeV and 480 GeV, decaying to a top quark and a neutral non-interacting particle lighter than 100 GeV, is excluded at 95\% confidence level.},
  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}
}
@article{OPUS4-12741,
  title     = {Measurement of the W boson polarization in top quark decays with the ATLAS detector},
  series = {Journal of High Energy Physics},
  volume    = {06},
  journal   = {Journal of High Energy Physics},
  number    = {88},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP06(2012)088},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127417},
  year      = {2012},
  abstract  = {This paper presents measurements of the polarization of W bosons in top quark decays, derived from \(t\overline{t}\) events with missing transverse momentum, one charged lepton and at least four jets, or two charged leptons and at least two jets. Data from pp collisions at a centre-of-mass energy of 7 TeV were collected with the ATLAS experiment at the LHC and correspond to an integrated luminosity of 1.04 fb\(^{-1}\). The measured fractions of longitudinally, left- and right-handed polarization are F\(_0\) = 0.67 ± 0.07, F\(_L\) = 0.32 ± 0.04 and F\(_R\) = 0.01 ± 0.05, in agreement with the Standard Model predictions. As the polarization of the W bosons in top quark decays is sensitive to the Wtb vertex Lorentz structure and couplings, the measurements were used to set limits on anomalous contributions to the Wtb couplings.},
  language  = {en}
}