Affleck-Dine leptogenesis with triplet Higgs

Abstract

We study an extension of the supersymmetric standard model including a pair of electroweak triplet Higgs $Δ$ and ${\bar Δ}$. The neutrinos acquire Majorana masses mediated by these triplet Higgs fields rather than the right-handed neutrinos. The successful leptogenesis for baryogenesis can be realized after the inflation through the Affleck-Dine mechanism on a flat manifold consisting of $Δ$, ${\bar Δ}$, ${\tilde e}^c$ (anti-slepton), even if the triplet Higgs mass $M_Δ$ is much larger than the gravitino mass $m_{3/2} \sim 10^3 {\rm GeV}$. Specifically, due to the effects of the potential terms provided with the superpotential terms $M_Δ{\bar Δ} Δ$, $(λ_{L /} / 2M) {\bar Δ} {\bar Δ} e^c e^c$, $(λ_Δ/ 2M) {\bar Δ} Δ{\bar Δ} Δ$ ($λ_{L /} / λ_Δ\sim 0.3 - 3$), the phases of $Δ$, ${\bar Δ}$, ${\tilde e}^c$ are rotated at the time with the Hubble parameter $H \sim M_Δ$, producing generally the asymmetry with fraction $ε_L \sim 0.1$. If $M_Δ$ is large enough, this early leptogenesis can be completed before the thermal effects take place.