@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{OPUS4-12797,
  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{OPUS4-12751,
  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{OPUS4-12741,
  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}
}
@article{OPUS4-12735,
  title     = {Measurement of inclusive two-particle angular correlations in pp collisions with the ATLAS detector at the LHC},
  series = {Journal of High Energy Physics},
  volume    = {05},
  journal   = {Journal of High Energy Physics},
  number    = {157},
  organization    = {ATLAS Collaboration},
  doi       = {10.1007/JHEP05(2012)157},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127350},
  year      = {2012},
  abstract  = {We present a measurement of two-particle angular correlations in proton- proton collisions at √s=900 GeV and 7 TeV. The collision events were collected during 2009 and 2010 with the ATLAS detector at the Large Hadron Collider using a single-arm minimum bias trigger. Correlations are measured for charged particles produced in the kinematic range of transverse momentum p\(_T\)  > 100 MeV and pseudorapidity |η| < 2.5. A complex structure in pseudorapidity and azimuth is observed at both collision energies. Results are compared to PYTHIA 8 and HERWIG++ as well as to the AMBT2B, DW and Perugia 2011 tunes of PYTHIA 6. The data are not satisfactorily described by any of these models.},
  language  = {en}
}