Exploring high scale seesaw models through a supersymmetric portal

TL;DR

This paper investigates how supersymmetric high-scale seesaw models can leave detectable signatures in Higgs-slepton couplings, suggesting potential signals at future high-energy collider phases.

Contribution

It demonstrates that high-scale supersymmetric seesaw models can produce observable effects in Higgs-slepton interactions at future collider energies.

Findings

Current bounds prevent detection at HL-LHC.

High-Energy LHC could detect signals in single lepton channel.

Signatures depend on large Yukawa couplings in supersymmetric seesaw models.

Abstract

The seesaw scale is a priori unknown. If the seesaw scale is low, one may directly look for the new particles predicted by seesaw models. If the seesaw scale is high, such an approach is unfeasible. We show that in some supersymmetric seesaw models the large Yukawa couplings of high scale seesaw models leave their fingerprints to Higgs-slepton couplings and that this can result in decays of the type $\tilde{\nu}_{2}\rightarrow \tilde{\nu}_{1}h$ in Type-I and Type-III seesaw models and $\tilde{\ell}^{\pm}_{2}\rightarrow \tilde{\ell}^{\pm}_{1}h$ in the latter. Unfortunately the current exclusion bounds make it impossible to see a significant signal even at the High-Luminosity phase of the LHC. In this paper, we highlight that the High-Energy phase of the LHC (with $\sqrt{s}=27$~TeV) could afford one with some sensitivity to those in the single lepton channel.