Unifying baryogenesis with dark matter production

We here propose a mechanism that predicts, at early times, both baryon asymmetry and dark matter origin and that recovers the spontaneous baryogenesis during the reheating. Working with $U(1)$-invariant quark $Q$ and lepton $L$ effective fields, with an interacting term that couples the evolution of Universe's environment field $\psi$, we require a spontaneous symmetry breaking and get a pseudo Nambu-Goldstone boson $\theta$. The pseudo Nambu-Goldstone boson speeds the Universe up during inflation, playing the role of inflaton, enabling baryogenesis to occur. Thus, in a quasi-static approximation over $\psi$, we impressively find both baryon and dark matter quasi-particle production rates, unifying \emph{de facto} the two scenarios. Moreover, we outline particle mixing and demonstrate dark matter takes over baryons. Presupposing that $\theta$ field energy density dominates as baryogenesis stops and employing recent limits on reheating temperature, we get numerical bounds over dark matter constituent, showing that the most likely dark matter boson would be consistent with MeV-scale mass candidates. Finally, we briefly underline our predictions are suitable to explain the the low-energy electron recoil event excess between $1$ and $7$~keV found by the \texttt{XENON1T} collaboration.