Explaining $Ω_{Baryon} \approx 0.2 Ω_{Dark}$ through 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 ($Ω_B \approx 0.05$), non-baryonic dark matter ($Ω_{Dark} \approx 0.22$) and dark energy ($Ω_Λ \approx 0.7$). We recently proposed that ordinary matter was synthesised from mirror matter, motivated by the argument that the observed similarity of $Ω_B$ and $Ω_{Dark}$ suggests an underlying similarity between the fundamental properties of ordinary and dark matter particles. In this paper we generalise the previous analysis by considering a wider class of effective operators that non-gravitationally couple the ordinary and mirror sectors. We find that while all considered operators imply $Ω_{Dark} = $ few$\times Ω_B$, only a subset quantitatively reproduce the observed ratio $Ω_B/Ω_{Dark} \approx 0.20$. The $\sim 1$ eV mass scale induced through these operators hints at a connection with neutrino oscillation physics.

minor changes, some references added, about 10 pages