WIMPless Dark Matter from Non-Abelian Hidden Sectors with Anomaly-Mediated Supersymmetry Breaking

TL;DR

This work develops WIMPless dark matter within anomaly-mediated SUSY breaking by analyzing non-Abelian hidden sectors, primarily SU($N$) gauge theories, and their connections to the MSSM. It shows that the hidden LSP can be stable or can decay to visible Winos via heavy connectors, yielding the correct relic density through the WIMPless relation $\frac{m_X^2}{g_X^4}$ and the AMSB scaling, while respecting cosmological and BBN constraints. The study identifies multiple qualitative regimes, including pure hidden sectors with self-interacting DM, hidden sectors with connectors that produce MSSM Wino DM, and scenarios with light hidden Goldstones, each with distinctive cosmology and potential observational signatures. Across these models, gauge coupling unification remains intact and the visible superpartners can remain relatively light, making the framework highly predictive and testable with future cosmological, astrophysical, and collider data.

Abstract

In anomaly-mediated supersymmetry breaking (AMSB) models, superpartner masses are proportional to couplings squared. Their hidden sectors therefore naturally contain WIMPless dark matter, particles whose thermal relic abundance is guaranteed to be of the correct size, even though they are not weakly-interacting massive particles (WIMPs). We study viable dark matter candidates in WIMPless AMSB models with non-Abelian hidden sectors and highlight unusual possibilities that emerge in even the simplest models. In one example with a pure SU(N) hidden sector, stable hidden gluinos freeze out with the correct relic density, but have an extremely low, but natural, confinement scale, providing a framework for self-interacting dark matter. In another simple scenario, hidden gluinos freeze out and decay to visible Winos with the correct relic density, and hidden glueballs may either be stable, providing a natural framework for mixed cold-hot dark matter, or may decay, yielding astrophysical signals. Last, we present a model with light hidden pions that may be tested with improved constraints on the number of non-relativistic degrees of freedom. All of these scenarios are defined by a small number of parameters, are consistent with gauge coupling unification, preserve the beautiful connection between the weak scale and the observed dark matter relic density, and are natural, with relatively light visible superpartners. We conclude with comments on interesting future directions.