arXiv subjects
Publications and source records attributed to Alberto Mariotti.
We study dynamical supersymmetry breaking in vector-like superconformal N=1 gauge theories. We find appropriate deformations of the superpotential to overcome the problem of the instability of the non supersymmetric vacuum. The request for long lifetime translates into constraints on the physical couplings which in this regime can be controlled through efficient RG analysis.
We give a general formulation of semi-direct gauge mediation of supersymmetry breaking where the messengers interact with the hidden sector only through a weakly gauged group. Using this general formulation, we provide an explicit proof that the MSSM gaugino masses are vanishing to leading order in the gauge couplings. On the other hand, the MSSM sfermion masses have, generically, a non-vanishing leading contribution. We discuss how such a mechanism can successfully be combined with other mediation schemes which give tachyonic sfermions, such as sequestered anomaly mediation and some direct gauge mediation models.
We consider semi-direct gauge mediation models of supersymmetry breaking where the messengers are composite fields and their supersymmetric mass is naturally generated through quartic superpotential couplings. We show that such composite messenger models can be easily embedded in quiver gauge theories arising from D-branes at Calabi-Yau singularities, and argue that semi-direct gauge mediation is in fact a very natural option for supersymmetry breaking in D-brane models. We provide several explicit examples and discuss their salient phenomenological properties.
We investigate supersymmetric models for dark matter which is represented by pseudomoduli in weakly coupled hidden sectors. We propose a scheme to add a dark matter sector to quiver gauge theories with metastable supersymmetry breaking. We discuss the embedding of such scheme in string theory and we describe the dark matter sector in terms of D7 flavour branes. We explore the phenomenology in various regions of the parameters.
We investigate features of duality in three dimensional N=2 Chern-Simons matter theories conjectured to describe M2 branes at toric Calabi Yau four-fold singularities. For 3D theories with non-chiral 4D parents we propone a Seiberg-like duality which turns out to be a toric duality. For theories with chiral 4D parents we discuss the conditions under which that Seiberg-like duality leads to toric duality. We comment on such duality in 3D theories without 4D parents.
We study the relation between stringy instantons and strong dynamics effects in type IIB toric quiver gauge theories. By exploiting the involutive property of Seiberg duality we relate the classical constraint on the moduli space of the gauge theory with the stringy instanton contribution to the superpotential. The result holds for unitary, orthogonal and symplectic gauge groups.
We analyze two loop quantum corrections for pseudomoduli in O'Raifeartaigh like models. We argue that R-symmetry can be spontaneously broken at two loop in non supersymmetric vacua. We provide a basic example with this property. We discuss on phenomenological applications.
We employ generalized complex geometry to investigate supersymmetric embeddings of D-brane probes in a large class of SU(2) structure manifolds. This class includes the gravity dual of mass deformation and marginal beta deformation of N=4 SYM gauge theory. We find supersymmetric configurations of D-branes with different dimensionality and propose their interpretation in the dual gauge theory.