TY  - JOUR
T1  - A search for \(t\overline t\) resonances with the ATLAS detector in 2.05 fb\(^{−1}\) of proton-proton collisions at √s=7 TeV
JF  - European Physical Journal C
N2  - A search for top quark pair resonances in final states containing at least one electron or muon has been performed with the ATLAS experiment at the CERN Large Hadron Collider. The search uses a data sample corresponding to an integrated luminosity of 2.05 fb\(^{−1}\), which was recorded in 2011 at a proton-proton centre-of-mass energy of 7 TeV. No evidence for a resonance is found and limits are set on the production cross-section times branching ratio to \(t\overline t\) for narrow and wide resonances. For narrow Z′ bosons, the observed 95 % Bayesian credibility level limits range from 9.3 pb to 0.95 pb for masses in the range of m Z′=500 GeV to m\(_{Z′}\)=1300 GeV. The corresponding excluded mass region for a leptophobic topcolour Z′ boson (Kaluza-Klein gluon excitation in the Randall-Sundrum model) is m\(_{Z′}\)<880 GeV (m\(_{gKK}\)<1130 GeV).
KW  - dilepton invariant mass
KW  - dilepton channel
KW  - jet channel
KW  - top quark mass
KW  - heavy flavour quark
KW  - reconstructed mass spectrum
KW  - muon channel
KW  - single top production
KW  - electron energy deposition
KW  - multijet background
KW  - non-prompt lepton
KW  - light quark jet
KW  - jet sample
KW  - pair invariant mass
KW  - event selcetion cut
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127959
VL  - 72
IS  - 2083
ER  - 
TY  - JOUR
T1  - Measurement of the top quark mass with the template method in the \(t\overline t\)→lepton+jets channel using ATLAS data
JF  - The European Physical Journal C
N2  - The top quark mass has been measured using the template method in the \(t\overline t\)→lepton+jets channel based on data recorded in 2011 with the ATLAS detector at the LHC. The data were taken at a proton-proton centre-of-mass energy of √s=7 TeV and correspond to an integrated luminosity of 1.04 fb\(^{−1}\). The analyses in the e+jets and μ+jets decay channels yield consistent results. The top quark mass is measured to be m\(_{top}\)=174.5±0.6\(_{stat}\)±2.3\(_{syst}\) GeV.
KW  - JES uncertainty
KW  - jet energy scale
KW  - top quark mass
KW  - jet channel
KW  - single top quark
KW  - jet energy scale uncertainty
KW  - systematic uncertainty
KW  - calorimeter response
KW  - simulated signal event
KW  - top quark decay
KW  - jet reconstruction efficiency
KW  - jet energy measurement
KW  - light quark jet
KW  - single top quark production
KW  - inclusive jet sample
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128912
VL  - 72
IS  - 2046
ER  - 
TY  - JOUR
T1  - Search for second generation scalar leptoquarks in pp collisions at √s=7 TeV with the ATLAS detector
JF  - The European Physical Journal C
N2  - The results of a search for the production of second generation scalar leptoquarks are presented for final states consisting of either two muons and at least two jets or a muon plus missing transverse momentum and at least two jets. A total of 1.03 fb\(^{−1}\) integrated luminosity of proton-proton collision data produced by the Large Hadron Collider at s√=7 TeV and recorded by the ATLAS detector is used for the search. The event yields in the signal regions are found to be consistent with the Standard Model background expectations. The production of second generation leptoquarks is excluded for a leptoquark mass m\(_{LQ}\)<594 (685) GeV at 95 % confidence level, for a branching ratio of 0.5 (1.0) for leptoquark decay to a muon and a quark.
KW  - jet energy scale
KW  - top quark mass
KW  - multi-jet background
KW  - simulated event sample
KW  - SM background
KW  - acceptance time efficiency
KW  - top quark contribution
KW  - top quark pair
KW  - primary vertex
KW  - single top quark production
KW  - signal cross section
KW  - systematic uncertainty
KW  - single top quark
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128957
VL  - 72
IS  - 2151
ER  - 
TY  - JOUR
T1  - Measurement of the top quark mass in the t\(\overline{t}\)→ lepton+jets and t\(\overline{t}\)→ dilepton channels using \(\sqrt {s}\)=7 TeV ATLAS data
JF  - European Physical Journal C: Particles and Fields
N2  - The top quark mass was measured in the channels t\(\overline{t}\) → lepton+jets and t\(\overline{t}\) → dilepton (lepton = e,μ) based on ATLAS data recorded in 2011. The data were taken at the LHC with a proton–proton centre-of-mass energy of \(\sqrt {s}\) = 7 TeV and correspond to an integrated luminosity of 4.6 fb\(^{-1}\). The t\(\overline{t}\) → lepton+jets analysis uses a three-dimensional template technique which determines the top quark mass together with a global jet energy scale factor (JSF), and a relative b-to-light-jet energy scale factor(bJSF), where the terms b-jets and light-jets refer to jets originating from b-quarks and u, d, c, s-quarks or gluons, respectively. The analysis of the t\(\overline{t}\) → dilepton channel exploits a one-dimensional template method using the m\(_{lb}\) observable, defined as the average invariant mass of the two lepton+b-jet pairs in each event. The top quark
mass is measured to be 172.33±0.75(stat + JSF + bJSF)±1.02(syst) GeV, and 173.79 ± 0.54(stat) ± 1.30(syst) GeV in the t\(\overline{t}\) → lepton+jets and t\(\overline{t}\) → dilepton channels, respectively. The combination of the two results yields m\(_{top}\) =172.99 ± 0.48(stat) ± 0.78(syst) GeV, with a total uncertainty of 0.91 GeV.
KW  - top quark mass
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149890
VL  - 75
IS  - 7
ER  -