[PDF] Top 20 A search for flavour changing neutral currents in top quark decays in pp collision data collected with the ATLAS detector at √s=7 TeV

... same flavour and opposite charges, the yield from these backgrounds can be extrapolated from the number of observed data events with three leptons of any flavour (e or µ), but with the same ...and ... See full document

... ment with the expected limit of BR(t → q Z) < 8 × 10 − 4 . Acknowledgments We thank CERN for the very successful oper- ation of the LHC, as well as the support staff from our institutions without whom ATLAS ... See full document

... identify top-quark decays and reconstruct the top-quark momentum for data collected with the ATLAS detector at a centre-of-mass energy of 7 ... See full document

... ing solenoid providing a 2 T axial magnetic field, electromagnetic and hadron calorimeters, and a muon spectrometer (MS). The ID covers the pseudorapidity range | η | < 2 . 5. It consists of silicon pixel, silicon ... See full document

... The ATLAS detector [36] consists of an inner detector for tracking surrounded by a super- conducting solenoid providing a 2 T magnetic field, electromagnetic and hadronic calorime- ters, and a muon ... See full document

... The ATLAS detector [36] consists of an inner detector for tracking surrounded by a super- conducting solenoid providing a 2 T magnetic field, electromagnetic and hadronic calorime- ters, and a muon ... See full document

... It consists of silicon pixel, semi-conductor micro-strip, and transition radiation tracking detectors. Lead/liquid-argon (LAr) sampling calorimeters provide electromagnetic (EM) energy measurements with high granularity. ... See full document

... The ATLAS [23] detector at the LHC [18] covers the pseudorapidity 1 range |η| < ...inner detector (ID) is composed of three subsystems: the pixel detector, the semiconductor tracker and the ... See full document

... preshower detector is located in front of the ECAL ...The detector is nearly hermetic, allowing momentum balance measurements in the plane transverse to the beam ... See full document

... of top quarks. This takes into account the width of the top quark, spin correlations between the production and decay, and the b quark mass in the anomalous and SM ...processes: top ... See full document

... H. Ghazlane 135b , B. Giacobbe 20a , S. Giagu 132a,132b , V. Giangiobbe 12 , P. Giannetti 124a,124b , B. Gibbard 25 , S. M. Gibson 77 , M. Gilchriese 15 , T. P. S. Gillam 28 , D. Gillberg 30 , G. ... See full document

... S. Bedikian 176 , V.A. Bednyakov 64 , C.P. Bee 83 , L.J. Beemster 105 , M. Begel 25 , S. Behar Harpaz 152 , P.K. Behera 62 , M. Beim- forde 99 , C. Belanger-Champagne 85 , P.J. Bell 49 , W.H. Bell 49 , G. ... See full document

... inner detector and muon spectrometer, and their momenta are determined from a combined fit to these two measure- ...inner detector and to have at least three hits in each of the inner, middle, and outer ... See full document

... between the barrel and the end cap calorimeters is ex- cluded. Electron candidates are formed from clusters of cells reconstructed in the electromagnetic calorimeter as- sociated with a charged particle track in the ... See full document

... G. Aad 48 , B. Abbott 111 , J. Abdallah 11 , S. Abdel Khalek 115 , A.A. Abdelalim 49 , O. Abdinov 10 , B. Abi 112 , M. Abolins 88 , O.S. AbouZeid 158 , H. Abramowicz 153 , H. Abreu 136 , E. Acerbi 89a , 89b , B.S. ... See full document

... The high-threshold TRT hit fraction, f HT , and the cluster dispersion, R , are thus chosen as the distinguishing var- iables between the signal and background, and are shown in Fig. 1. The main physics background ... See full document

... √ s = 7 TeV ...the top mass were performed in both lepton + jets and dilepton decay channels, both in agreement with pre- vious measurements at the ...a search for t ¯ tZ production. ... See full document

... For the t-channel measurements, the event selection re- quires exactly one electron or muon candidate, exactly two or three jets and E miss T > 25 GeV (7 TeV) or 30 GeV (8 TeV). A trigger matching ... See full document

... lightest scalar top is mostly the partner of the right-handed top quark. The branching fraction of ~ t ! t ~ 0 1 is set to 100% and the top-quark mass is set to 172.5 GeV. Signal cross ... See full document

... In the lepton p T and dilepton invariant mass ranges relevant to this study, the level of the background is best estimated using a data-driven method, rather than by MC simulation where the number of events is low ... See full document