294,300 research outputs found
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Measurements of top quark pair relative differential cross-sections with ATLAS in pp collisions at root s=7 TeV
Full text linkATLAS Collaboration Contributor: Paul Douglas Jackson of SLAC National Accelerator Laboratory, Stanford CA, United States of AmericaMeasurements are presented of differential cross-sections for top quark pair production in pp collisions at √s = 7 TeV relative to the total inclusive top quark pair production cross-section. A data sample of 2.05 fb⁻¹ recorded by the ATLAS detector at the Large Hadron Collider is used. Relative differential cross-sections are derived as a function of the invariant mass, the transverse momentum and the rapidity of the top quark pair system. Events are selected in the lepton (electron or muon) + jets channel. The background-subtracted differential distributions are corrected for detector effects, normalized to the total inclusive top quark pair production cross-section and compared to theoretical predictions. The measurement uncertainties range typically between 10 % and 20 % and are generally dominated by systematic effects. No significant deviations from the Standard Model expectations are observed.The ATLAS Collaboratio
Transcepts: Connecting Entity Representations Across Conceptual Views on Spatial Information (Short Paper)
Full text linkAnalysts interpret geographic and other spatial data to check the validity of methods in reaching an analytical goal. However, the meaning of data is elusive. The same data may constitute one concept in one view and another concept in another. For example, the same set of air pollution points may be regarded as field values if they are considered pollution measurements and objects if they are considered locations of measurement devices. In this work we adopt a framework of conceptual spaces and viewpoints and show how entity representations in one semantic interpretation may be related to entity representations in others in terms of what we call transcepts. A transcept captures which things represent the same entity. We define and use transcepts in the framework to explain how different views of geographic data may relate to one another
Search for top quark decays t → qH with H → γγ using the ATLAS detector
Full text linkA search is performed for flavour-changing neutral currents in the decay of a top quark to an up-type (c, u) quark and a Higgs boson, where the Higgs boson decays to two photons. The proton-proton collision data set used corresponds to 4.7 fb-1 at √ = 7TeV and 20.3fb-1 at √ = 8TeV collected by the ATLAS experiment at the LHC. Top quark pair events are searched for in which one top quark decays to qH and the other decays to bW. Both the hadronic and the leptonic decay modes of the W boson are used. No significant signal is observed and an upper limit is set on the t → qH branching ratio of 0.79 at the 95% confidence level. The corresponding limit on the tqH coupling combination λtcH 2 + λtuH 2 is 0.17
Measurement of the top quark pair production cross section in <i>pp</i> collisions at √s=7 TeV in dilepton final states with ATLAS
Full text linkA measurement of the production cross section of top quark pairs (t<span style="text-decoration: overline">t</span>) in proton–proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the Large Hadron Collider is reported. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. Using a data sample corresponding to an integrated luminosity of 35 pb<sup>−1</sup>, a t<span style="text-decoration: overline">t</span> production cross section σ t<span style="text-decoration: overline">t</span> = 177 ± 20(stat.) ± 14 (syst.) ± 7(lum.) pb is measured for an assumed top quark mass of <i>mt</i>=172.5 GeV. A second measurement requiring at least one jet identified as coming from a <i>b</i> quark yields a comparable result, demonstrating that the dilepton final states are consistent with being accompanied by <i>b</i>-quark jets. These measurements are in good agreement with Standard Model predictions
Measurement of the top quark charge in pp collisions at s√=7 TeV with the ATLAS detector
Full text linkA measurement of the top quark electric charge is carried out in the ATLAS experiment at the Large Hadron Collider using 2.05 fb−1 of data at a centre-of-mass energy of 7 TeV. In units of the elementary electric charge, the top quark charge is determined to be 0.64 ± 0.02 (stat.) ± 0.08 (syst.) from the charges of the top quark decay products in single lepton tt¯ candidate events. This excludes models that propose a heavy quark of electric charge −4/3, instead of the Standard Model top quark, with a significance of more than 8σ
An isogeny of K3 surfaces
Full text linkIn a recent paper the L-series of K3 surfaces from a certain one-parameter family was described in terms of those of a particular family of elliptic curves. The Tate conjecture predicts the existence of a correspondence between these K3 surfaces and certain Kummer surfaces related to these elliptic curves. A geometric construction of this correspondence is given here, using other's results on Nikulin involutions.
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