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Subject: search.filters.subject.Supersymmetry and Duality

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    Natural supersymmetry and dynamical flavour with meta-stable vacua
    (Springer, 2014-07-29) Abela, Steven; McGarrie, Moritz
    We show how gauged flavour breaking and N = 1 supersymmetry breaking can be dynamically aligned to produce natural models. Supersymmetry is broken in a metastable vacuum, while a weakly gauged flavour symmetry is identified with an SU (3) F subgroup of the global symmetry of the SQCD model. We find that alignment can easily occur either through strongly coupled flavour models, with SQCD bound states playing the role of flavons, or entirely weakly coupled and renormalizable models with elementary SU (3) F adjoint flavons. In both cases it is essential that the SU (3) F breaking, and hence all the flavour structure, is driven dynamically by the SUSY breaking. The resulting flavour gauge mediation in conjunction with the usual gauge mediation contribution leads to naturally light third generations squarks, with first and second generations above.
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    Indefinite theta functions for counting attractor backgrounds
    (Springer, 2014-10-03) Cardoso, Gabriel Lopes; Ciraficia, Michele; Nampurib, Suresh
    In this note, we employ indefinite theta functions to regularize canonical partition functions for single-center dyonic BPS black holes. These partition functions count dyonic degeneracies in the Hilbert space of four-dimensional toroidally compactified heterotic string theory, graded by electric and magnetic charges. The regularization is achieved by viewing the weighted sums of degeneracies as sums over charge excitations in the near-horizon attractor geometry of an arbitrarily chosen black hole background, and eliminating the unstable modes. This enables us to rewrite these sums in terms of indefinite theta functions. Background independence is then implemented by using the transformation property of indefinite theta functions under elliptic transformations, while modular transformations are used to make contact with semi-classical results in supergravity.