# Type I + II Seesaw in a Two Higgs Doublet Model

## TL;DR

This paper explores how to incorporate neutrino masses into Two Higgs Doublet Models using type I and II seesaw mechanisms, proposing models with distinct phenomenological features.

## Contribution

It introduces novel realizations of type I and II seesaw mechanisms within the 2HDM-U(1) framework, addressing neutrino mass generation.

## Key findings

- Multiple models with type I, II, and combined seesaw mechanisms developed.
- Models exhibit diverse phenomenological implications.
- Demonstrates compatibility of seesaw mechanisms with 2HDM-U(1).

## Abstract

Two Higgs Doublet Models (2HDM) are popular extensions of the Standard Model for several reasons, but do not explain neutrino masses. In this work, we investigate how one can incorporate neutrino masses within the framework of the 2HDM-U(1), where U(1) is an abelian gauge symmetry used to nicely address the absence of flavor changing neutral currents in 2HDM. In particular, we explore realizations of the type I and type II seesaw since they are mechanisms that we dote on for being able to generate elegantly small active neutrino masses. We show that one can build several models featuring type I, type II and type I+II seesaw mechanism with different phenomenological implications.