Resolving a challenging supersymmetric low-scale seesaw scenario at the ILC

TL;DR

This paper explores a low-scale supersymmetric seesaw model with light right-handed neutrinos and Higgsino-like neutralinos, analyzing its detectability at the LHC and future linear colliders, and updating constraints on slepton masses.

Contribution

It provides an updated analysis of slepton mass constraints from LHC data and demonstrates the potential of future colliders to discover or exclude challenging supersymmetric scenarios.

Findings

Sleptons as light as 175 GeV are consistent with current LHC data.

Upcoming LHC runs can discover or exclude sleptons around 300 GeV.

Future 1 TeV e+e- colliders can detect sleptons in difficult scenarios and measure spectra with 1-3% accuracy.

Abstract

We investigate a scenario inspired by natural supersymmetry, where neutrino data is explained within a low-scale seesaw scenario. For this the Minimal Supersymmetric Standard Model is extended by adding light right-handed neutrinos and their superpartners, the R-sneutrinos. Moreover, we consider the lightest neutralinos to be Higgsino-like. We first update a previous analysis and assess to which extent does existing LHC data constrain the allowed slepton masses. Here we find scenarios where sleptons with masses as low as 175 GeV are consistent with existing data. However, we also show that the upcoming run will either discover or rule out sleptons with masses of 300 GeV, even for these challenging scenarios. We then take a scenario which is on the borderline of observability of the upcoming LHC run assuming a luminosity of 300 fb$^{-1}$. We demonstrate that a prospective international $e^+ e^-$ linear collider with a center of mass energy of 1 TeV will be able to discover sleptons in scenarios which are difficult for the LHC. Moreover, we also show that a measurement of the spectrum will be possible within 1-3 percent accuracy.