Many Leptons at the LHC from the NMSSM

TL;DR

This paper proposes a specific NMSSM parameter space benchmark that predicts a distinctive multi-lepton signal at the LHC with minimal background, enabling potential detection and mass measurements of supersymmetric particles.

Contribution

It introduces a new benchmark scenario in the NMSSM that results in a clean, multi-lepton signal with no jets, facilitating experimental detection and mass difference measurements at the LHC.

Findings

Multi-lepton signals can be detected at 5 sigma with limited data.

Kinematic edges in lepton invariant mass distributions are observable.

Mass differences of neutralinos can be measured from the data.

Abstract

We present a benchmark in the parameter space of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) that provides for a dramatic multi-lepton signal and no jets containing 5 or more leptons resulting from the cascade decays of the third lightest neutralino, $\chi^{0}_{3}$, and the lightest chargino, $\chi^{\pm}_{1}$, via light charged sleptons. This is a very clean signal with almost no Standard Model (SM) background. In some cases, a total signal of $\ge 3 $leptons + 0 jets can be detected at the $5 \sigma$ level at the LHC running at $\sqrt{s}=7$ TeV with approximately 3 fb$^{-1}$ of data and with less than 1 fb$^{-1}$ when running at $\sqrt{s}=14$ TeV. In addition, kinematic edges in the invariant mass distributions of 2, 3, and 4 leptons are easily detectable with large integrated luminosities ($\sim 600$ fb$^{-1}$) which can lead to simple measurements of the mass differences of heavy particles in the decay chains, including all combinations of the three lightest neutralinos.