Out Of This World Supersymmetry Breaking

TL;DR

The paper proposes that SUSY breaking in a hidden, higher-dimensional sector is transmitted to the MSSM predominantly via the super-Weyl anomaly, with the SM confined to a 3-brane and breaking occurring off-brane. In a setup where at least one extra dimension is compactified below the Planck scale, this sequestered arrangement renders anomaly-mediated contributions to gaugino and scalar masses finite and predictive, while bulk radiative effects can provide flavor-blind scalar masses and help solve the slepton tachyon problem. The resulting spectrum is highly constrained: gaugino masses align with MSSM beta functions, yielding a light wino-like LSP and characteristic mass hierarchies; sleptons require bulk contributions to be viable, and the framework naturally mitigates flavor and CP problems and offers a potential μ problem solution. The model also remains compatible with gauge-gravity unification in some parameter regimes and predicts striking collider signatures, providing a concrete route to testing the existence of extra dimensions via the superpartner spectrum.

Abstract

We show that in a general hidden sector model, supersymmetry breaking necessarily generates at one-loop a scalar and gaugino mass as a consequence of the super-Weyl anomaly. We study a scenario in which this contribution dominates. We consider the Standard Model particles to be localized on a (3+1)-dimensional subspace or ``3-brane'' of a higher dimensional spacetime, while supersymmetry breaking occurs off the 3-brane, either in the bulk or on another 3-brane. At least one extra dimension is assumed to be compactified roughly one to two orders of magnitude below the four-dimensional Planck scale. This framework is phenomenologically very attractive; it introduces new possibilities for solving the supersymmetric flavor problem, the gaugino mass problem, the supersymmetric CP problem, and the mu-problem. Furthermore, the compactification scale can be consistent with a unification of gauge and gravitational couplings. We demonstrate these claims in a four-dimensional effective theory below the compactification scale that incorporates the relevant features of the underlying higher dimensional theory and the contribution of the super-Weyl anomaly. Naturalness constraints follow not only from symmetries but also from the higher dimensional origins of the theory. We also introduce additional bulk contributions to the MSSM soft masses. This scenario is very predictive: the gaugino masses, squark masses, and $A$ terms are given in terms of MSSM renormalization group functions.