Breaking the Dark Force

TL;DR

This work builds a concrete Weak-Scale SUSY realization of a GeV-scale dark force to address DM-related anomalies such as PAMELA/ATIC and DAMA/INTEGRAL. By sequestering the dark sector from the SUSY-breaking hidden sector and employing a generalized Giudice-Masiero mechanism, the model naturally generates weak-scale DM masses and GeV-scale dark gauge bosons, with AMSB and FI-term effects furnishing the mediator mass. The resulting spectrum includes coexisting heavy and light DM states (iHDM and LDM), a rich mix of scalar and Majorana fermions, and decay channels to SM states through kinetic mixing and higher-dimension operators, yielding potential lepton-jet collider signals while respecting BBN and relic abundance constraints. The framework provides a testable link between SUSY breaking, dark-sector dynamics, and astrophysical signatures, clarifying when lepton-jet signals may or may not be observed at colliders and outlining avenues for further numerical and phenomenological exploration.

Abstract

Recently Arkani-Hamed, Finkbeiner, Slatyer and Weiner proposed a unified explanation to the set of experimental and observational anomalies with possible connections to Dark Matter (DM). A central role is played by GeV scale "dark" gauge bosons exchanged by the weak scale DM. Motivated by this proposal, we build an explicit model of DM in the context of Weak Scale Supersymmetry (SUSY). We employ high-scale SUSY-breaking and invoke the Giudice-Masiero mechanism to generate the weak scale DM masses. By sequestering the dark sector from the SUSY-breaking "hidden" sector, it naturally acquires GeV scale soft masses that help generate the dark gauge boson mass. The visible MSSM sector is not fully sequestered and acquires gaugino-mediated soft terms at the weak scale. This hierarchy of scales naturally leads to the Sommerfeld enhancement of DM annihilations needed to account for the electron/positron excesses in the PAMELA and ATIC experiments. The possibility of co-existing species of DM is used to show how the INTEGRAL and DAMA anomalies can both be explained. We study the cosmological constraints on the new stable or long-lived light particles that appear in our models. We discuss the lepton-jet collider signals suggested by Arkani-Hamed and Weiner, and find that they are not guaranteed in our construction.

Figures (4)

• Figure 1: A qualitative picture of extra-dimensional sequestering.
• Figure 2: The mass spectrum of the dark sector, measured in units of GeV, plotted against various values of $\lambda$. The values which have been chosen for this plots are: $g_D=0.4,\ {m_{\frac{3}{2}}}=110\ {\rm GeV}, \kappa=1,\ \epsilon=10^{-4},\ \tan \beta= 10$. Here, as well as on the following plots, the red (dotted) and the green (dashed) lines denote the scalars from $S$ and $\bar{T}$ admixtures, the blue (dashed-dotted) line denotes a Dirac fermion from $S$ and $\bar{T}$. A cyan solid thick line denotes the mass of the gauge boson, while the brown and the black thin lines denote Majorana fermions from the gauge multiplet and $T$.
• Figure 3: The mass spectrum of the dark sector. The values chosen for the right-hand side picture are $g_D=0.5,\ {m_{\frac{3}{2}}}=100\ {\rm GeV},\ \kappa=0.8,\ \epsilon=10^{-3},\ \tan \beta=8$ and for the left-hand side picture $g_D=0.6,\ {m_{\frac{3}{2}}}=85\ {\rm GeV},\ \kappa=2,\ \epsilon=5\times 10^{-4},\ \tan \beta=30$. Again the mass is measured in units of GeV, the red dotted line and the green dashed line denote scalars from $S$ and $\bar{T}$ admixtures, the blue dased-dotted line denotes a Dirac fermion from $S$ and $\bar{T}$. A cyan solid thick line denotes the mass of the gauge boson, while the brown and the black thin lines denote Majorana fermions from the gauge multiplet and $T$.
• Figure 4: An effective operator, responsible for the decay of $\bar{T}$ is formed at two-loop level (supergraph notations has been used). The insertions on the photonic lines denote $\epsilon$ and the cross denotes $\mu$-term insertion.