Soft supersymmetry breaking from stochastic superspace

Abstract

We propose a new realization of softly broken supersymmetric theories as theories defined on stochastic superspace. At the classical level, the supersymmetry breaking is parameterized in terms of a single (in general complex) mass parameter, $\xi$, describing the stochasticity of the Grassmannian superspace coordinates. In the context of the standard model with stochastic supersymmetry, the structure of the soft breaking terms has various characteristic features that can be tested in LHC experiments. Namely, at the classical level, the $B_{\mu}$ parameter, the universal soft trilinear coupling $A_0$, the universal gaugino mass $m_{1/2}$ and the universal scalar mass $m_0$ are given solely in terms of $\xi$; there are no other arbitrary parameters. The relations are $B_\mu = \xi^*$, $A_0 = 2\xi^*$, $m_{1/2} = |\xi|/2$ and $m_0 = 0$. At the quantum level, these relations hold at a certain scale $\Lambda$ which is a second free parameter. The soft scalar masses, zero at tree-level, are induced radiatively through the renormalization group equations at one-loop. With this pattern of soft breaking terms, large supersymmetric contributions to FCNC processes are avoided. As a concrete illustration of the proposed formalism, we consider a minimal model, which is just the constrained MSSM with the stochastic superspace relations amongst the soft-breaking parameters imposed at the scale $\Lambda$. We show that this theory is phenomenologically viable for a certain region in the $(\xi,\Lambda)$ parameter space. Some sensible extensions of the minimal model are then briefly discussed.