Research Outputs (School of Physics)

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Browsing Research Outputs (School of Physics) by Keyword "Beyond Standard Model"

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    Light third-generation squarks from flavour gauge messengers
    (Springer, 2014-04-10) Brummer, Felix; McGarrie, Moritz; Weiler, Andreas
    We study models of gauge-mediated supersymmetry breaking with a gauged horizontal SU(3)F symmetry acting on the quark superfields. If SU(3)F is broken nonsupersymmetrically by F -term vacuum expectation values, the massive gauge bosons and gauginos become messengers for SUSY breaking mediation. These gauge messenger fields induce a flavour-dependent, negative contribution to the soft masses of the squarks at one loop. In combination with the soft terms from standard gauge mediation, one obtains large and degenerate first- and second-generation squark masses, while the stops and sbottoms are light. We discuss the implications of this mechanism for the superparticle spectrum and for flavour precision observables. We also provide an explicit realization in a model with simultaneous SUSY and SU(3)F breaking.
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    Natural supersymmetry and unification in five dimensions
    (Springer Verlag, 2016-01) Abdalgabar, A.; Cornell, A.S.; Deandrea, A.; McGarrie, M.
    We explore unification and natural supersymmetry in a five dimensional extension of the standard model in which the extra dimension may be large, of the order of 1–10 TeV. Power law running generates a TeV scale At term allowing for the observed 125 GeV Higgs and allowing for stop masses below 2 TeV, compatible with a natural SUSY spectrum. We supply the full one-loop RGEs for various models and use metastability to give a prediction that the gluino mass should be lighter than 3.5 TeV for At ≥ −2.5 TeV, for such a compactification scale, with brane localised 3rd generation matter. We also discuss models in which only the 1st and 2nd generation of matter fields are located in the bulk. We also look at electroweak symmetry breaking in these models.