TY - JOUR T1 - Search for invisible particles produced in association with single-top-quarks in proton-proton collisions at \(\sqrt {s}\) = 8 TeV with the ATLAS detector JF - European Physical Journal C: Particles and Fields N2 - A search for the production of single-top-quarks in association with missing energy is performed in proton–proton collisions at a centre-of-mass energy of \(\sqrt {s}\) =8 TeV with the ATLAS experiment at the large hadron collider using data collected in 2012, corresponding to an integrated luminosity of 20.3 fb\(^{−1}\). In this search, the W boson from the top quark is required to decay into an electron or a muon and a neutrino. No deviation from the standard model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark. In the case of resonant production, for a spin-0 resonance with a mass of 500 GeV, an effective coupling strength above 0.15 is excluded at 95 % confidence level for the top quark and an invisible spin-1/2 state with mass between 0 and 100 GeV. In the case of non-resonant production, an effective coupling strength above 0.2 is excluded at 95 % confidence level for the top quark and an invisible spin-1 state with mass between 0 and 657 GeV. KW - single-top-quarks KW - proton-proton collision KW - ATLAS detector Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150134 VL - 75 IS - 2 ER - TY - JOUR T1 - Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at \(\sqrt {s}\) = 8 TeV using the ATLAS experiment JF - European Physical Journal C: Particles and Fields N2 - Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as R-hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns. A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data sample corresponding to an integrated luminosity of 18.4 fb\(^{−1}\) of pp collisions at \(\sqrt {s}\) = 8 TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on R-hadrons and chargino production are set. Gluino R-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95 % confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV. KW - ATLAS detector KW - charged heavy long-lived particles KW - proton-proton collision Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150149 VL - 75 IS - 9 ER - TY - JOUR T1 - Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at \(\sqrt {s}\) = 8 TeV with the ATLAS detector JF - European Physical Journal C: Particles and Fields N2 - Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb\(^{−1}\) of \(\sqrt {s}\) = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between E\(^{miss}_{T}\) > 150 GeV and E\(^{miss}_{T}\) > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presented. KW - ATLAS detector KW - energetic jet KW - proton-proton collision Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150152 VL - 75 IS - 7 ER - TY - JOUR T1 - Measurement of the production and lepton charge asymmetry of bosons in Pb+Pb collisions at \(\sqrt {^{S}NN}\) with the ATLAS detector JF - European Physical Journal C: Particles and Fields N2 - A measurement of W boson production in lead-lead collisions at \(\sqrt {^{S}NN}\)=2.76 TeV is presented. It is based on the analysis of data collected with the ATLAS detector at the LHC in 2011 corresponding to an integrated luminosity of 0.14 nb\(^{-1}\) and 0.15 nb\(^{-1}\) in the muon and electron decay channels, respectively. The differential production yields and lepton charge asymmetry are each measured as a function of the average number of participating nucleons ⟨N\(_{part}\)⟩ and absolute pseudorapidity of the charged lepton. The results are compared to predictions based on next-to-leading-order QCD calculations. These measurements are, in principle, sensitive to possible nuclear modifications to the parton distribution functions and also provide information on scaling of W boson production in multi-nucleon systems. KW - Higgs boson KW - lead-lead collision Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149889 VL - 75 IS - 1 ER - TY - JOUR T1 - Search for resonant diboson production in the ℓℓq\(\overline{q}\) final state in pp collisions at \(\sqrt {s}\) = 8 TeV with the ATLAS detector JF - European Physical Journal C: Particles and Fields N2 - This paper reports on a search for narrow resonances in diboson production in the ℓℓq\(\overline{q}\) final state using pp collision data corresponding to an integrated luminosity of 20 fb\(^{−1}\) collected at \(\sqrt {s}\) = 8 TeV with the ATLAS detector at the Large Hadron Collider. No significant excess of data events over the Standard Model expectation is observed. Upper limits at the 95 % confidence level are set on the production cross section times branching ratio for Kaluza–Klein gravitons predicted by the Randall–Sundrum model and for Extended Gauge Model W′ bosons. These results lead to the exclusion of mass values below 740 and 1590 GeV for the graviton and W′ boson respectively. KW - ATLAS detector KW - proton-proton collision KW - diboson production KW - resonances Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150171 VL - 75 IS - 2 ER - TY - JOUR T1 - 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 JF - European Physical Journal C: Particles and Fields N2 - 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. KW - ATLAS detector KW - Z boson KW - proton-proton-collision Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149970 VL - 75 IS - 5 ER - TY - JOUR T1 - Performance of the ATLAS muon trigger in pp collisions at \(\sqrt {s}\)= 8 TeV JF - European Physical Journal C: Particles and Fields N2 - 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. KW - LHC KW - proton-proton-collistion Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150032 VL - 75 IS - 3 ER - TY - JOUR T1 - Search for W' → tb → qqbb decays in pp collisions at \(\sqrt {s}\) = 8 TeV with the ATLAS detector JF - European Physical Journal C: Particles and Fields N2 - 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. KW - ATLAS detector KW - proton-proton collision Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150068 VL - 75 IS - 4 ER - TY - JOUR T1 - Determination of spin and parity of the Higgs boson in the WW\(^{*}\)→eνμν decay channel with the ATLAS detector JF - European Physical Journal C: Particles and Fields N2 - Studies of the spin and parity quantum numbers of the Higgs boson in the WW\(^{*}\)→eνμν final state are presented, based on proton–proton collision data collected by the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 20.3 fb\(^{-1}\) at a centre-of-mass energy of \(\sqrt {s}\)=8 TeV. The Standard Model spin-parity J\(^{CP}\)=0\(^{++}\) hypothesis is compared with alternative hypotheses for both spin and CP. The case where the observed resonance is a mixture of the Standard-Model-like Higgs boson and CP-even (J\(^{CP}\)=0\(^{++}\)) or CP-odd (J\(^{CP}\)=0\(^{+-}\)) Higgs boson in scenarios beyond the Standard Model is also studied. The data are found to be consistent with the Standard Model prediction and limits are placed on alternative spin and CP hypotheses, including CP mixing in different scenarios. KW - Higgs boson KW - spin KW - parity Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149632 VL - 75 IS - 5 ER - TY - BOOK ED - Hornung, Christoph ED - Lambrecht, Gabriella-Maria ED - Sendner, Annika T1 - Kommunikation und Repräsentation in den romanischen Kulturen. Festschrift für Gerhard Penzkofer N2 - Diese Festschrift ehrt den Romanisten und Slawisten Gerhard Penzkofer anlässlich seines 65. Geburtstags. Kolleginnen und Kollegen sowie Schülerinnen und Schüler, die Gerhard Penzkofer auf seinem bisherigen Weg unter anderem in München, Bamberg und Würzburg sowohl fachlich als auch persönlich nahestanden, publizieren hier Beiträge, die von seinen Forschungen inspiriert sind. Im Zentrum dieser Untersuchungen, die den italienischen, französischen und spanischen Sprachraum umschließen, steht das Verhältnis von Kommunikation und Repräsentation. Dabei umfassen die Beiträge Aspekte, die historisch vom Mittelalter bis zum 20. Jahrhundert und thematisch von der mittelalterlichen Exempelsammlung bis zur postdiktatorialen Geschichtskonstruktion reichen. KW - Kommunikation KW - Repräsentation KW - Spanische Literatur KW - Französische Literatur KW - Italienische Literatur KW - Kommunikation KW - Literatur KW - Geschichte KW - Repräsentation KW - Romanische Sprachen KW - communication KW - spanish literature KW - french literature KW - italian literature Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-152021 UR - https://www.avm-verlag.de/detailview?no=5477-055 SN - 9783954770557 PB - AVM.edition CY - München ER -