Probing Seesaw in an Adjoint SUSY SU(5) Model at LHC

TL;DR

This paper proposes an extended supersymmetric SU(5) model that predicts testable triplet scalars at the LHC, integrating multiple seesaw mechanisms for neutrino mass generation, and discusses its collider and proton decay phenomenology.

Contribution

The paper introduces a symmetric adjoint SUSY SU(5) model with specific triplet scalar and fermion mass predictions, enabling LHC testing of type II seesaw.

Findings

Triplet scalars around 100 GeV can be produced at LHC.

Model predicts combined type I, II, and III seesaw neutrino masses.

Proton decay predictions are discussed.

Abstract

The SU(5) GUT model extended with fermions in the adjoint $24_F$ representation predicts triplet fermions in the 100 GeV mass range, opening up the possibility of testing seesaw at LHC. However, once the model is supersymmerized, the triplet fermion mass is constrained to be close to the GUT scale for the gauge couplings to unify. We propose an extension of the SUSY SU(5) model where type II seesaw can be tested at LHC. In this model we add a matter chiral field in the adjoint $\hat{24}_F$ representation and Higgs chiral superfields in the symmetric $\hat{15}_H$ and $\hat{\bar{15}}_H$ representations. We call this the symmetric adjoint SUSY SU(5) model. The triplet scalar and triplet fermion masses in this model are predicted to be in the 100 GeV and $10^{13}$ GeV range respectively, while the mass of the singlet fermion remains unconstrained. This gives a type I plus type II plus type III seesaw mass term for the neutrinos. The triplet scalars with masses $\sim 100$ GeV range can be produced at the LHC. We briefly discuss the collider phenomenology and predictions for proton decay in this model.