Atomki anomaly and the Secluded Dark Sector

TL;DR

This paper explores the Atomki anomaly as a potential sign of a new light vector boson mediating interactions between the Standard Model and dark matter, proposing models where dark matter self-interactions address small-scale structure issues.

Contribution

It introduces simple effective models linking the Atomki anomaly to secluded dark matter, highlighting the role of fermionic dark matter in solving small-scale structure problems.

Findings

Secluded dark matter models can satisfy thermal relic abundance.

Dark matter self-interactions can be sufficiently large to resolve small-scale structure puzzles.

The Atomki anomaly may indicate a new light vector boson connecting to dark matter.

Abstract

The Atomiki anomaly can be interpreted as a new light vector boson. If such a new particle exists, it could be a mediator between the Standard Model sector and the dark sector including the dark matter. We discussed some simple effective models with these particles. In the models, the secluded dark matter models are good candidates to satisfy the thermal relic abundance. In particular, we found that the dark matter self-interaction can be large enough to solve the small scale structure puzzles if the dark matter is a fermion.