Big Bang Nucleosynthesis Constraint on $B$-mesogenesis

Abstract

$B$-mesogenesis is a low-temperature baryogenesis mechanism, that uses $CP$-violation of the $B$ mesons in the standard model to fulfill the Sakharov conditions. It requires a late period of matter domination by a scalar field $\Phi$ that decays into $b\bar{b}$ quarks, reheating the Universe below the QCD phase transition. We investigate the impact of this mechanism on Big Bang Nucleosynthesis, with respect to the reheating temperature $T_{rh}$, and the mass of $\Phi$. Injection of hadrons skewing neutron/proton interconversions are the most important effect, followed by neutrino heating from $\Phi$ decays. For $M_{\Phi }\lesssim 100$GeV, $T_{rh}$ must be $\gtrsim 10$MeV.

arXiv comment7 pages, 7 figures