Hunting Quasi-Degenerate Higgsinos

Understand

We present a new strategy to uncover light, quasi-degenerate Higgsinos, a likely ingredient in a natural supersymmetric model.

• Our strategy focuses on Higgsinos with inter-state splittings of O(5-50) GeV that are produced in association with a hard, initial state jet and decay via off-shell gauge bosons to two or more leptons and missing energy, $pp \to j + \text{MET}\, + 2^+\, \ell$.
• The additional jet is used for triggering, allowing us to significantly loosen the lepton requirements and gain sensitivity to small inter-Higgsino splittings.
• Focusing on the two-lepton signal, we find the seemingly large backgrounds from diboson plus jet, $\bar tt$ and $Z/\gamma^* + j$ can be reduced with careful cuts, and that fake backgrounds appear minor.