Searching for super-WIMPs in leptonic heavy meson decays

Abstract

We study constraints on the models of bosonic super-weakly interacting particle (super-WIMP) dark matter (DM) with DM masses $m_X\sim \mathcal{O}(1-100)$ keV from leptonic decays $M\to \ell {\bar{\nu }}_{\ell }+X$, where $M=B^{\pm },D^{\pm },D_s^{\pm }$ is a heavy meson state. We focus on two cases where $X$ denotes either a light pseudoscalar (axion-like), or a light vector state that couples to the standard model (SM) through kinetic mixing. We note that for a small DM mass these decays are separately sensitive to DM couplings to quarks, but not its mass.

Comments: 17 pages, 3 figures, 6 tables