Speaker
Description
$U(1)_{B-L}$ gauged extensions of the Standard Model provide a simple and phenomenological rich framework for neutrino mass generation. However, dark matter and the stability of the Higgs potential are often addressed as separate issues. In this talk, we discuss a model in which these three aspects are linked. The model contains two sterile pseudo-Dirac fermion pairs in the visible sector and an additional $Z_2$-odd pair in the dark sector. Light neutrino masses arise from a hybrid mechanism, combining a tree-level inverse seesaw in the visible sector with a scotogenic-like contribution from the dark sector.
We study the resulting active-sterile mixing and the constraints from charged lepton flavor violation and collider searches. The additional sterile fermions also affect the running of the Higgs quartic coupling, lowering the scale of vacuum instability. We show that when a metastable electroweak vacuum is assumed, the resulting bound on the Higgs mass is dictated by the BSM spectrum, linking the smallness of the Higgs mass directly to vacuum metastability. We also discuss dark matter phenomenology, were the $Z'$ resonance is the most favorable region for obtaining the observed relic abundance.