ExplainingΩbaryon≈0.2Ωdarkthrough the synthesis of ordinary matter from mirror matter: A more general analysis

Abstract

The emerging cosmological picture is of a spatially flat universe composed predominantly of three components: ordinary baryons $({\ensuremath{\Omega}}_{B}\ensuremath{\approx}0.05),$ nonbaryonic dark matter $({\ensuremath{\Omega}}_{\mathrm{dark}}\ensuremath{\approx}0.22)$ and dark energy $({\ensuremath{\Omega}}_{\ensuremath{\Lambda}}\ensuremath{\approx}0.7).$ We recently proposed that ordinary matter was synthesized from mirror matter, motivated by the argument that the observed similarity of ${\ensuremath{\Omega}}_{B}$ and ${\ensuremath{\Omega}}_{\mathrm{dark}}$ suggests an underlying similarity between the fundamental properties of ordinary and dark matter particles. In this paper we generalize the previous analysis by considering a wider class of effective operators that nongravitationally couple the ordinary and mirror sectors. We find that while all considered operators imply ${\ensuremath{\Omega}}_{\mathrm{dark}}=\mathrm{few}\ifmmode\times\else\texttimes\fi{}{\ensuremath{\Omega}}_{B},$ only a subset quantitatively reproduce the observed ratio ${\ensuremath{\Omega}}_{B}/{\ensuremath{\Omega}}_{\mathrm{dark}}\ensuremath{\approx}0.20.$ The $\ensuremath{\sim}1\mathrm{eV}$ mass scale induced through these operators hints at a connection with neutrino oscillation physics.