Affleck–Dine leptogenesis with triplet Higgs

Abstract

We study an extension of the supersymmetric standard model including a pair of electroweak triplet Higgs $\Delta$ and ${\bar \Delta}$. 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 $\Delta$, ${\bar \Delta}$, ${\tilde e}^c$ (anti-slepton), even if the triplet Higgs mass $M_\Delta$ 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 $M_\Delta {\bar \Delta} \Delta$, $(\lambda_{L /} / 2M) {\bar \Delta} {\bar \Delta} e^c e^c$, $(\lambda_\Delta / 2M) {\bar \Delta} \Delta {\bar \Delta} \Delta$ ($\lambda_{L /} / \lambda_\Delta \sim 0.3 - 3$), the phases of $\Delta$, ${\bar \Delta}$, ${\tilde e}^c$ are rotated at the time with the Hubble parameter $H \sim M_\Delta$, producing generally the asymmetry with fraction $\epsilon_L \sim 0.1$. If $M_\Delta$ is large enough, this early leptogenesis can be completed before the thermal effects take place.