Speaker
Description
The Type-II seesaw is a minimal extension of the Standard Model in which an electroweak scalar triplet generates Majorana neutrino masses through its vacuum expectation value. This model gives rise to rich collider phenomenology involving charged and neutral scalar states. In this work, we investigate mass spectra with neutral scalars lighter than their charged partners. We map neutral decay modes and lifetimes, identify regions with long-lived particles, and examine how scalar couplings affect the competition between visible and invisible decays. We also calculate production cross sections and include charged scalar cascades in the predicted neutral yields. These results motivate searches for signatures that can be poorly covered by conventional prompt decay analyses. Our broader goal is to systematically address these gaps and exploit the HL-LHC potential to test the origin of neutrino masses. The resulting search strategies may also probe related scalar sectors in more extended theories.