Scalar versus fermionic top partner interpretations of $t\bar t + E_T^{\rm miss}$ searches at the LHC

Understand

We assess how different ATLAS and CMS searches for supersymmetry in the $t\bar t + E_T^{\rm miss}$ final state at Run 1 of the LHC constrain scenarios with a fermionic top partner and a dark matter candidate.

• We find that the efficiencies of these searches in all-hadronic, 1-lepton and 2-lepton channels are quite similar for scalar and fermionic top partners.
• Therefore, in general, efficiency maps for stop-neutralino simplified models can also be applied to fermionic top-partner models, provided the narrow width approximation holds in the latter.
• Owing to the much higher production cross-sections of heavy top quarks as compared to stops, masses up to $m_T\approx 850$ GeV can be excluded from the Run 1 stop searches.