Browsing by Subject "topology"

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    Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
    (2016) Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; Aben, R; Abolins, M; AbouZeid, O S; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, B S; Adamczyk, L; Adams, D L; Adelman, J; Adomeit, S; Adye, T; Affolder, A A; Agatonovic-Jovin, T; Agricola, J; Aguilar-Saavedra, J A; Ahlen, S P; Ahmadov, F; Aielli, G; Akerstedt, H; Åkesson, T P A; Akimov, A V; Alberghi, G L; Albert, J; Albrand, S; Alconada Verzini, M J
    In the pp → tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at √s = 8 TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯ > 0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2 < |yt| − |yt¯| < 2 is measured to be 4.2 ± 3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.
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    Open Access
    Topological studies of three related metal-organic frameworks of Gd III and 5-nitroisophthalate
    (2012) Davies, Kate; Bourne, Susan A; Öhrström, Lars; Oliver, Clive L
    The reaction of 5-nitroisophthalic acid (H(2)NIA) with Gd(NO(3))(3)·6H(2)O in DMF afforded three new metal-organic frameworks: [Gd(NIA)(1.5)(DMF)(2)]·DMF (I), [Gd(2)(NIA)(3)(DMF)(4)]·xH(2)O (II) and [Gd(4)(NIA)(6)(DMF)(5.5)(H(2)O)(3)]·4DMF·H(2)O (III). These compounds can be prepared through a variety of methods. Compounds (I) and (II) are more reproducibly formed than compound (III). Network analysis revealed (I) to have a (4(12).6(3))-pcu topology, while (II) displays a (4(2).8(4))(4(2).8(4))-pts topology. Compound (III) was found to present the uncommon 4,5,6T11 topological net, which combines aspects of both the pcu and pts topologies. The short symbol of this net is (4(4).6(2))(4(6).6(4))(2)(4(8).6(6).8).