Search for Light Dark Matter in Rare Meson Decays

TL;DR

This paper explores how rare meson decays with missing energy can effectively detect sub-GeV dark matter, providing complementary constraints to direct detection experiments, especially for momentum-dependent interactions.

Contribution

It demonstrates the potential of rare meson decay processes to probe light dark matter in a mass range difficult for direct detection, using a generic $Z^{\u2192}$ portal model.

Findings

Derived upper limits on $Z^{\u2192}$ portal parameters from meson decay data.

Showed meson decays complement direct detection constraints for sub-GeV dark matter.

Highlighted sensitivity to momentum-dependent interaction operators.

Abstract

Current dark matter direct detection experiments have low sensitivity to sub-GeV dark matter. In this work, we demonstrate that rare $B$ and $K$ meson decays with missing energy in the final state can serve as efficient probes in this mass range. We analyze a generic $Z^{\prime}$ portal dark matter model and derive upper limits on its parameters from experimental bounds on the rare $B$ and $K$ meson decays. Our results show that such meson decay processes provide complementary constraints to current direct detection experiments for sub-GeV dark matter, particularly for interaction forms mediated by dark matter momentum-dependent operators.