Gauge Mediation in the NMSSM with a Light Singlet: Sparticles within the Reach of LHC Run II

TL;DR

This paper presents a simple, predictive gauge mediation model within the NMSSM that achieves a 125 GeV Higgs with relatively light stops, predicting observable signals at LHC Run II.

Contribution

It introduces a model combining minimal gauge mediation and NMSSM without direct Higgs-messenger couplings, explaining the Higgs mass and LEP excess with light stops and singlet mixing.

Findings

Higgs mass of 125 GeV achieved with stops as light as 1.1 TeV

Higgs-singlet mixing explains LEP excess

LHC Run II has promising discovery prospects with cross-sections of 10-100 fb

Abstract

Relatively light stops in gauge mediation models are usually made compatible with the Higgs mass of 125 GeV by introducing direct Higgs-messenger couplings. We show that such couplings are not necessary in a simple and predictive model that combines minimal gauge mediation and the next-to-minimal supersymmetric standard model (NMSSM). We show that one can obtain a 125 GeV Standard Model-like Higgs boson with stops as light as 1.1 TeV, thanks to the mixing of the Higgs with a singlet state at ${\cal O}(90-100)$ GeV that can explain the LEP excess. In this scenario the singlet-higgs-higgs superfields coupling $\lambda$ is small and $\tan\beta$ large. Sparticle searches at the LHC may come with additional $b-$jets or taus and may involve displaced vertices. The sparticle production cross-section at the 13 TeV LHC can be ${\mathcal O}(10-100)$ fb, leading to great prospects for discovery in the early phase of LHC Run II.