No Arabic abstract
We study vacuum structure of N=1 supersymmetric quiver gauge theories which can be realized geometrically by D brane probes wrapping cycles of local Calabi-Yau three-folds. In particular, we show that the A_2 quiver theory with gauge group U(N_1) times U(N_2) with N_1 / 2 < N_2 < 2N_1 / 3 has a regime with an infrared free description that is partially magnetic and partially electric. Using this dual description, we show that the model has a landscape of inequivalent meta-stable vacua where supersymmetry is dynamically broken and all the moduli are stabilized. Each vacuum has distinct unbroken gauge symmetry. B-terms generated by the supersymmetry breaking give rise to gaugino masses at one-loop, and we are left with the bosonic pure Yang-Mills theory in the infrared. We also identify the supersymmetric vacua in this model using their infrared free descriptions and show that the decay rates of the supersymmetry breaking vacua into the supersymmetric vacua can be made parametrically small.
In this paper we consider quiver gauge theories with fractional branes whose infrared dynamics removes the classical supersymmetric vacua (DSB branes). We show that addition of flavors to these theories (via additional non-compact branes) leads to local meta-stable supersymmetry breaking minima, closely related to those of SQCD with massive flavors. We simplify the study of the one-loop lifting of the accidental classical flat directions by direct computation of the pseudomoduli masses via Feynman diagrams. This new approach allows to obtain analytic results for all these theories. This work extends the results for the $dP_1$ theory in hep-th/0607218. The new approach allows to generalize the computation to general examples of DSB branes, and for arbitrary values of the superpotential couplings.
Starting from a peculiar orientifold projection proposed long ago by Angelantonj and Cardella, we elaborate on a novel perturbative scenario that involves only D-branes, together with the two types of orientifold planes ${rm O}_{pm}$ and anti-orientifold planes $overline{{rm O}}_{pm}$. We elucidate the microscopic ingredients of such models, connecting them to a novel realization of brane supersymmetry breaking. Depending on the position of the D-branes in the internal space, supersymmetry can be broken at the string scale on branes, or alternatively only at the massive level. The main novelty of this construction is that it features no NS-NS disk tadpoles, while avoiding open-string instabilities. The one-loop potential, which depends on the positions of the D-branes, is minimized for maximally broken, nonlinearly realized supersymmetry. The orientifold projection and the effective field theory description reveal a soft breaking of supersymmetry in the closed-string sector. In such models it is possible to decouple the gravitino mass from the value of the scalar potential, while avoiding brane instabilities.
We investigate supersymmetry breaking meta-stable vacua in N=2, SU(2)times U(1) gauge theory with N_f=2 massless flavors perturbed by the addition of small N=1 preserving mass terms in a presence of a Fayet-Iliopoulos term. We derive the low energy effective theory by using the exact results of N=2 supersymmetric QCD and examine the effective potential. At the classical level, the theory has supersymmetric vacua on Coulomb and Higgs branches. We find that supersymmetry on the Coulomb branch is dynamically broken as a consequence of the strong dynamics of SU(2) gauge symmetry while the supersymmetric vacuum on the Higgs branch remains. We also estimate the lifetimes of the local minima on the Coulomb branch. We find that they are sufficiently long and therefore the local vacua we find are meta-stable.
We discuss spontaneous supersymmetry (SUSY) breaking mechanisms by means of modulated vacua in four-dimensional ${cal N} =1$ supersymmetric field theories. The SUSY breaking due to spatially modulated vacua is extended to the cases of temporally and lightlike modulated vacua, using a higher-derivative model with a chiral superfield, free from the Ostrogradsky instability and the auxiliary field problem. For all the kinds of modulated vacua, SUSY is spontaneously broken and the fermion in the chiral superfield becomes a Goldstino. We further investigate the stability of the modulated vacua. The vacua are (meta)stable if the vacuum energy density is non-negative. However, the vacua become unstable due to the presence of the ghost Goldstino if the vacuum energy density is negative. Finally, we derive the relation between the presence of the ghost Goldstino and the negative vacuum energy density in the modulated vacua using the SUSY algebra.
We calculate the low energy effective action of massless and massive complex linear superfields coupled to a massive U(1) vector multiplet. Our calculations include superspace higher derivative corrections and therefore go beyond previous results. Among the superspace higher derivatives we find that terms which lead to a deformation of the auxiliary field potential and may break supersymmetry are also generated. We show that the supersymmetry breaking vacua can only be trusted if there exists a hierarchy between the higher order terms. A renormalization group analysis shows that generically a hierarchy is not generated by the quantum corrections.