A CP-violating phase in a two Higgs triplet scenario : some phenomenological implications

TL;DR

This paper explores a two Higgs triplet model with a CP-violating phase, predicting distinctive collider signatures such as Higgs plus same-sign dilepton peaks from doubly-charged scalar decays, relevant for LHC searches.

Contribution

It introduces a CP-violating phase in a two Higgs triplet scenario and analyzes its phenomenological implications, including dominant decay modes and potential collider signals.

Findings

Large CP phase increases mass splitting of doubly-charged scalars.

Dominant decay mode: $H_1^{++} ightarrow H_2^{++} h$.

Potential for observing Higgs plus same-sign dilepton signals at the LHC.

Abstract

We consider a scenario where, along with the usual Higgs doublet, two scalar triplets are present. The extension of the triplet sector is required for the Type~II mechanism for the generation of neutrino masses, if this mechanism has to generate a neutrino mass matrix with two-zero texture. One CP-violating phase has been retained in the scalar potential of the model, and all parameters have been chosen consistently with the observed neutrino mass and mixing patterns. We find that a large phase ($\gtrsim 60^{\circ}$) splits the two doubly-charged scalar mass eigenstates wider apart, so that the decay $H_1^{++} \rightarrow H_2^{++} h$ is dominant (with h being the $125$ GeV scalar). We identify a set of benchmark points where this decay dominates. This is complementary to the situation, reported in our earlier work, where the heavier doubly-charged scalar decays as $H_1^{++} \rightarrow H_2^+ W^+$. We point out the rather spectacular signal, ensuing from $H_1^{++} \rightarrow H_2^{++} h$, in the form of Higgs plus same-sign dilepton peak, which can be observed at the Large Hadron Collider.