Heavy Dark Matter Through the Higgs Portal

TL;DR

The paper investigates heavy dark matter that interacts with the MSSM exclusively through Higgs-sector couplings (the Higgs Portal), showing that a thermal relic density consistent with observations can be achieved for masses up to approximately 30 TeV. It introduces a supersymmetric Higgs-portal model with singlets and a near-degenerate scalar partner, and computes the relic density including non-perturbative Sommerfeld corrections, revealing that heavy DM is viable and that indirect-detection signals can be dramatically enhanced in low-velocity environments. The work also discusses direct-detection prospects via Higgs exchange and outlines a Fat-Higgs UV completion that naturally accommodates large portal couplings without destabilizing the electroweak sector. Together, these results position Higgs-portal dark matter as a compelling alternative to MSSM neutralinos, with distinctive indirect-detection signatures and a concrete UV-complete framework for its couplings.

Abstract

Motivated by Higgs Portal and Hidden Valley models, heavy particle dark matter that communicates with the supersymmetric Standard Model via pure Higgs sector interactions is considered. We show that a thermal relic abundance consistent with the measured density of dark matter is possible for masses up to $\sim 30\tev$. For dark matter masses above $\sim 1\tev$, non-perturbative Sommerfeld corrections to the annihilation rate are large, and have the potential to greatly affect indirect detection signals. For large dark matter masses, the Higgs-dark-matter-sector couplings are large and we show how such models may be given a UV completion within the context of so-called "Fat-Higgs" models. Higgs Portal dark matter provides an example of an attractive alternative to conventional MSSM neutralino dark matter that may evade discovery at the LHC, while still being within the reach of current and upcoming indirect detection experiments.

Figures (9)

• Figure 1: Generic Sommerfeld diagram. The "blob" vertex represents all possible $S$-wave annihilations of the incoming states including s-channel, t-channel and annihilation via contact interactions.
• Figure 2: Type I annihilation diagrams for the scalar $s$ states.
• Figure 3: Sommerfeld diagram for scalar annihilations.
• Figure 4: Type II: Annihilation of $s$ with $\tilde{s}$.
• Figure 5: Sommerfeld diagrams for annihilation of $s$ and $\tilde{s}$.