Neutrino Masses, Dark Matter and B-L Symmetry at the LHC

TL;DR

This paper proposes a hybrid seesaw mechanism within a B-L extended Standard Model to explain neutrino masses and dark matter, analyzing collider signatures and constraints from various experiments.

Contribution

It introduces a novel loop-level hybrid seesaw model with a dark matter candidate and studies its phenomenology at the LHC.

Findings

Dark matter candidate identified within the model.

Predictions for decay signatures of new scalars at the LHC.

Constraints from neutrino data and lepton flavor violation analyzed.

Abstract

We establish a hybrid seesaw mechanism to explain small neutrino masses and predict cold dark matter candidate in the context of the B-L gauge symmetry extension of the Standard Model. In this model a new scalar doublet and two new fermion singlets are introduced at loop-level beyond the minimal Type I seesaw. The lightest particle inside the loop can be dark matter candidate. We study in detail the constraints from neutrino oscillation data, lepton flavor violating processes and cosmological observation. We also explore the predictions of the decays of the new charged scalars in each spectrum of neutrino masses and show the most optimistic scenarios to distinguish the spectra. We consider the pair production of the stable fermion associated with two observable SM charged leptons at the LHC, which occurs in a two-step cascade decay of the new gauge boson Z' and the new charged scalars stand as intermediate particles. The masses of missing dark matter and its parent particle can be well-determined in such production topology.