203 research outputs found

    The finiteness of the four dimensional antisymmetric tensor field model in a curved background

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    A renormalizable rigid supersymmetry for the four dimensional antisymmetric tensor field model in a curved space-time background is constructed. A closed algebra between the BRS and the supersymmetry operators is only realizable if the vector parameter of the supersymmetry is a covariantly constant vector field. This also guarantees that the corresponding transformations lead to a genuine symmetry of the model. The proof of the ultraviolet finiteness to all orders of perturbation theory is performed in a pure algebraic manner by using the rigid supersymmetry.Comment: 23 page

    Post-imperialism, postcolonialism and beyond: towards a periodisation of cultural discourse about colonial legacies

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    Taking German history and culture as a starting point, this essay suggests a historical approach to reconceptualising different forms of literary engagement with colonial discourse, colonial legacies and (post-) colonial memory in the context of Comparative Postcolonial Studies. The deliberate blending of a historical, a conceptual and a political understanding of the ‘postcolonial’ in postcolonial scholarship raises problems of periodisation and historical terminology when, for example, anti-colonial discourse from the colonial period or colonialist discourse in Weimar Germany are labelled ‘postcolonial’. The colonial revisionism of Germany’s interwar period is more usefully classed as post-imperial, as are particular strands of retrospective engagement with colonial history and legacy in British, French and other European literatures and cultures after 1945. At the same time, some recent developments in Francophone, Anglophone and German literature, e.g. Afropolitan writing, move beyond defining features of postcolonial discourse and raise the question of the post-postcolonial

    Precise measurement of the Ds+D^+_s lifetime at Belle II

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    We measure the lifetime of the Ds+D_s^+ meson using a data sample of 207 fb1^{-1} collected by the Belle II experiment running at the SuperKEKB asymmetric-energy e+ee^+ e^- collider. The lifetime is determined by fitting the decay-time distribution of a sample of 116×103116\times 10^3 Ds+ϕπ+D_s^+\rightarrow\phi\pi^+ decays. Our result is \tau^{}_{D^+_s} = (498.7\pm 1.7\,^{+1.1}_{-0.8}) fs, where the first uncertainty is statistical and the second is systematic. This result is significantly more precise than previous measurements.Comment: 7 pages, 4 figures, to be submitted to Physical Review Letter

    CMS physics technical design report : Addendum on high density QCD with heavy ions

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    Peer reviewe

    Measurement of the Λc+\Lambda_c^+ lifetime

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    An absolute measurement of the Λc+\Lambda^{+}_c lifetime is reported using Λc+pKπ+\Lambda_c^+\rightarrow pK^-\pi^+ decays in events reconstructed from data collected by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the Υ(4S)\Upsilon(4S) resonance, is 207.2~\mbox{fb}^{-1}. The result, τ(Λc+)=203.20±0.89(stat)±0.77(syst)\tau(\Lambda^{+}_c) = 203.20 \pm 0.89 \,\mathrm{(stat)} \pm 0.77 \,\mathrm{(syst)} fs, is the most precise measurement to date and is consistent with previous determinations.Comment: Accepted for publication in PR

    Search for an invisible ZZ^\prime in a final state with two muons and missing energy at Belle II

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    The LμLτL_{\mu}-L_{\tau} extension of the standard model predicts the existence of a lepton-flavor-universality-violating ZZ^{\prime} boson that couples only to the heavier lepton families. We search for such a ZZ^\prime through its invisible decay in the process e+eμ+μZe^+ e^- \to \mu^+ \mu^- Z^{\prime}. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7fb1^{-1}. We find no excess over the expected standard-model background. We set 90%\%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×1033 \times 10^{-3} at low ZZ^{\prime} masses to 1 at ZZ^{\prime} masses of 8GeV/c2GeV/c^{2}
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