@article{OPUS4-14990,
  title     = {Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at \(\sqrt {s}\)=7TeV},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {4},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3373-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149905},
  pages     = {158},
  year      = {2015},
  abstract  = {The mass of the top quark is measured in a data set corresponding to 4.6  fb\(^{-1}\) of proton-proton collisions with centre-of-mass energy \(\sqrt {s}\)=7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top-antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified b-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jet to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the W boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of m\(_{t}\)= 175.1 ± 1.4 (stat.) ± 1.2 (syst.) GeV.},
  language  = {en}
}
@article{OPUS4-14305,
  title     = {Search for a CP-odd Higgs boson decaying to Zh in pp collisions at \(\sqrt{s}\)=8 TeV with the ATLAS detector},
  series = {Physics Letters B},
  volume    = {744},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2015.03.054},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143050},
  pages     = {163-183},
  year      = {2015},
  abstract  = {A search for a heavy, CP-odd Higgs boson, A, decaying into a Z boson and a 125 GeV Higgs boson, h, with the ATLAS detector at the LHC is presented. The search uses proton-proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb\(^{-1}\). Decays of CP-even h bosons to ττ or bb pairs with the Z boson decaying to electron or muon pairs are considered, as well as h→bb decays with the Z boson decaying to neutrinos. No evidence for the production of an A boson in these channels is found and the 95\% confidence level upper limits derived for σ(gg→A)×BR(A→Zh)×BR(h→f\(\bar{f}\)) are 0.098-0.013 pb for f=τ and 0.57-0.014 pb for f=b in a range of m\(_{A}\)=220-1000 GeVmA=220-1000 GeV. The results are combined and interpreted in the context of two-Higgs-doublet models.},
  language  = {en}
}
@article{OPUS4-13986,
  title     = {Search for s-channel single top-quark production in proton-proton collisions at \(\sqrt{s}\)=8 TeV with the ATLAS detector},
  series = {Physics Letters B},
  volume    = {740},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2014.11.042},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-139869},
  pages     = {118-136},
  year      = {2015},
  abstract  = {This Letter presents a search at the LHC for s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of 8 TeV. The analyzed data set was recorded by the ATLAS detector and corresponds to an integrated luminosity of 20.3 fb\(^{-1}\). Selected events contain one charged lepton, large missing transverse momentum and exactly two b-tagged jets. A multivariate event classifier based on boosted decision trees is developed to discriminate s-channel single top-quark events from the main background contributions. The signal extraction is based on a binned maximum-likelihood fit of the output classifier distribution. The analysis leads to an upper limit on the s-channel single top-quark production cross-section of 14.6 pb at the 95\% confidence level. The fit gives a cross-section of σs=5.0±4.3 pb, consistent with the Standard Model expectation.},
  language  = {en}
}