Fate of the false vacuum in a singlet-doublet fermion extension model with RG-improved effective action
We study the effective potential and the Renormalization Group(RG) improvement of the effective potential of Higgs boson in a model with singlet-doublet fermion extension of the Standard Model(SM), which is motivated by the research of dark matter candidate. We study the stability of the electroweak vacuum with the RG improved effective potential in this model beyond the SM. We show that in this model the RG improved effective potential at high energy scale can be quite different from the Higgs potential aided with running quartic self-coupling which is usually considered in literatures, contrary to the case of the SM in which the difference at high energy scale is accidentally small. Then we study the decay of the electroweak vacuum using the RG improved effective potential in this model beyond the SM. In this study we consider the quantum correction to the kinetic term in the effective action and consider the RG improvement of the kinetic term. Combining all these effects, we find that the decay rate of the false vacuum is slightly changed when calculated using the RG improved effective action.