Constraining Time Dependent Dark Matter Signals from the Sun

TL;DR

This paper investigates how the orbital motion of space-based detectors affects the observation of time-dependent signals from dark matter annihilation in the Sun, and uses non-observation to set limits on dark matter models.

Contribution

It provides a method to constrain dark matter signals by analyzing the expected time dependence in cosmic-ray electron fluxes and derives new limits from current space-based experiment data.

Findings

No significant time-dependent signals observed.

Derived 95% confidence level limits on dark matter annihilation.

Constraints on dark photon models comparable to supernova bounds.

Abstract

Dark matter (DM) particles captured by the Sun can produce high energy electrons outside the Sun through annihilating into meta-stable mediators. The corresponding cosmic-ray electron signals observed by the space-based experiments will be time dependent due to the orbital motion of the space-based detectors. The shape of this time dependence is predictable given the orbital information of the detectors. Since the high-energy CR electron (with energy E>100 GeV) fluxes are expected to be constant in time, non-observation of such time variation can be used to place upper limits on the DM annihilation cross section. We analyze the time dependence of dark matter cosmic-ray signals in three space-based experiments: AMS-02, DAMPE and CALET. Under the assumption that no time dependent signal is observed, we derive the 95% C.L. exclusion limits on the signal strength from the current data. We map our limits onto the parameter space of the dark photon model and find that the constraints are comparable with that derived from the supernova SN1987A.