Two Light Stops in the NMSSM and the LHC

TL;DR

This paper investigates the possibility of two light stops in the NMSSM, demonstrating their compatibility with LHC data and proposing dedicated search strategies for future collider runs to detect such scenarios.

Contribution

It introduces a viable scenario with two light stops in the NMSSM, compatible with current experimental constraints, and suggests new search channels for the LHC to discover them.

Findings

Light stops are compatible with LHC constraints and Higgs data.

Dedicated search strategies can potentially discover these stops in future LHC runs.

Signals with >5σ significance are possible with moderate luminosity.

Abstract

We study the viability of having two relatively light top squarks (`stops') in the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). Such light stops render the NMSSM rather `natural'. These are shown to be allowed by the relevant direct searches at the Large Hadron Collider (LHC) and to be compatible with the latest LHC results on the Higgs sector, other low energy electroweak constraints and recent constraints from the dark matter (DM) sector. We propose dedicated searches for such light stops at the LHC within a `simplified' scenario that may have a bino-like or a singlino-like neutralino LSP as the DM candidate and point out various final states carrying the imprint of their collective presence. Under certain circumstances, in such a scenario, presence of two light stops may give rise to final states which are not so typical in their search. Thorough studies at the detector level reveal the status of such a scenario after the 8 TeV run of the LHC and shed light on the prospects of its 13 and 14 TeV runs. In favorable regions of the NMSSM parameter space, with low-lying spectra, signals with significance $\gtrsim 5\sigma$ is possible with a few tens to a few hundreds of $\text{fb}^{-1}$ of integrated luminosity in diverse final states.