Searching for light dark matter in heavy meson decays

Abstract

Beauty and charm ${e}^{+}{e}^{\ensuremath{-}}$ factories running at resonance thresholds have unique capabilities for studies of the production of light dark matter particles in the decays of ${B}_{q}(D)$ meson pairs. We provide a comprehensive study of light dark matter production in heavy meson decays with missing energy $\mathrm{E\ensuremath{\llap{\not\;}}}$ in the final state, such as ${B}_{q}({D}^{0})\ensuremath{\rightarrow}\mathrm{E\ensuremath{\llap{\not\;}}}$ and ${B}_{q}({D}^{0})\ensuremath{\rightarrow}\ensuremath{\gamma}\mathrm{E\ensuremath{\llap{\not\;}}}$. We argue that such transitions can be studied at the current flavor factories (and future superflavor factories) by tagging the missing-energy decays with $B({D}^{0})$ decays ``on the other side.''