$\text{Dark}_{CP}$ Mesogenesis and New Implications for Collider Searches

Abstract: We introduce $\text{Dark}{CP}$ Mesogenesis in which Standard Model mesons, either $B{s,d}^0$, $B^\pm$ or $B_c^\pm$, undergo out-of-equilibrium dark CP violating decays to Standard Model and dark sector baryons. With order one CP violation in the dark sector, the observed baryon asymmetry of the Universe can then be generated with branching fractions as small as $2.7 \times 10^{-8}$ for the exotic decay of $B$-mesons into baryons and missing energy. This sets a lower limit on the branching fraction below which Mesogenesis becomes disfavored. This work therefore strongly encourages collider searches to target sensitivities one to three orders of magnitude below planned limits. For completeness, we further introduce a variant on $\text{Dark}_{CP}$ Mesogenesis involving dark lepton states. We conclude by laying out a roadmap for the complete exclusion (or discovery) of the Mesogenesis framework.