Discovering $E_6$ SUSY models in gluino cascade decays at the LHC

Abstract

We point out that the extra neutralinos and charginos generically appearing in a large class of $E_6$ inspired models lead to distinctive signatures from gluino cascade decays in comparison to those from the Minimal Supersymmetric Standard Model (MSSM). These signatures involve longer decay chains, more visible transverse energy, higher multiplicities of jets and leptons, and less missing transverse energy than in the MSSM. These features make the gluino harder to discover for certain types of conventional analyses, for example in the 6 jet channel we show that a 1 TeV MSSM gluino may resemble an 800 GeV $E_6$ gluino. However, the enriched lepton multiplicity provides enhanced 3- and 4-lepton signatures, which are much more suppressed in the case of the MSSM. As an example we analyse various scenarios in the E${}_6$SSM, demonstrating the utility of a \texttt{CalcHEP} model that we have now made publicly available on HEPMDB (High Energy Physics Models DataBase). After extensive scans over the parameter space, we focus on representative benchmark points. We perform detailed Monte Carlo analyses, concentrating on the 3-lepton channel at the 7, 8, and 14 TeV Large Hadron Collider (LHC), and demonstrate that $E_6$ inspired models are clearly distinguishable from the MSSM in gluino cascade decays. We emphasise to the LHC experimental groups that the distinctive features present in gluino cascade decays, such as those discussed here, not only represents a unique footprint of a particular model but also may provide the key to an earlier discovery of supersymmetry.

36 pages, 15 figures

References in corpus (11)

• Dark Matter Results from 225 Live Days of XENON100 Data
• Soft gluon resummation for the production of gluino-gluino and squark-antisquark pairs at the LHC
• Z' physics with early LHC data
• Search for narrow resonances in dilepton mass spectra in pp collisions at sqrt(s) = 7 TeV
• Gauge Coupling Unification in the Exceptional Supersymmetric Standard Model
• Leptogenesis in the Exceptional Supersymmetric Standard Model: flavour dependent lepton asymmetries
• Novel Higgs Decays and Dark Matter in the E(6)SSM
• Neutralino Dark Matter with Inert Higgsinos and Singlinos
• SLHAplus: a library for implementing extensions of the standard model
• Bino Dark Matter and Big Bang Nucleosynthesis in the Constrained E6SSM with Massless Inert Singlinos
• Early SUSY discovery at LHC without missing E_T: the role of multi-leptons

Cited by in corpus (5)

• NMSSM with a singlino LSP: possible challenges for searches for supersymmetry at the LHC
• Dark matter candidates in the constrained Exceptional Supersymmetric Standard Model
• Leptogenesis and Dark Matter-Nucleon Scattering Cross Section in the SE6SSM
• TeV-scale leptoquark searches at the LHC and their E${}_6$SSM Interpretation
• A Review of the Exceptional Supersymmetric Standard Model