Constraining sleptons at the LHC in a supersymmetric low-scale seesaw scenario

Nhell Cerna-Velazco,Thomas Faber,Werner Porod,Joel Jones-Pérez

doi:10.1140/epjc/s10052-017-5231-9

Nhell Cerna-Velazco, Thomas Faber + Show 2 more

Open Access

https://doi.org/10.1140/epjc/s10052-017-5231-9

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Abstract

We consider a scenario inspired by natural supersymmetry, where neutrino data is explained within a low-scale seesaw scenario. We extend the Minimal Supersymmetric Standard Model by adding light right-handed neutrinos and their superpartners, the R-sneutrinos, and consider the lightest neutralinos to be higgsino-like. We consider the possibilities of having either an R-sneutrino or a higgsino as lightest supersymmetric particle. Assuming that squarks and gauginos are heavy, we systematically evaluate the bounds on slepton masses due to existing LHC data.

Highlights

The discovery of the Higgs boson in the 8 TeV run of the LHC [1,2] marks one of the most important milestones in particle physics
While this completes the Standard Model (SM) particle-wise, several questions still remain open, for example: (i) Is it possible to include the SM in a grand unified theory where all gauge forces unify? (ii) Is there a particle physics explanation of the observed dark matter relic density? (iii) What causes the hierarchy in the fermion mass spectrum and why are neutrinos so much lighter than the other fermions? What causes the observed mixing patterns in the fermion sector? (iv) What stabilizes the Higgs mass at the electroweak scale?
This leads to bounds on the m E –m Lplane, which are shown in Fig. 4 for the case μ = 120 GeV and tan β = 10

Summary

Introduction

The discovery of the Higgs boson in the 8 TeV run of the LHC [1,2] marks one of the most important milestones in particle physics. Its mass is already known rather precisely: mh = 125.09 ± 0.21 (stat.) ± 0.11 (syst.) GeV [3], and the signal strength of various LHC searches has been found to be consistent with the SM predictions While this completes the Standard Model (SM) particle-wise, several questions still remain open, for example: (i) Is it possible to include the SM in a grand unified theory where all gauge forces unify? We consider here a supersymmetric model where neutrino data are explained via a minimal inverse seesaw scenario where the gauge-singlet neutrinos have masses in the range O (keV) to O (100 GeV). Appendices A and B give the complete formulas for the neutrino and sneutrino masses

The model

Set-up

Higgsino LSP

R-sneutrino LSP

Conclusions