Monojet plus soft dilepton signal from light higgsino pair production at LHC14

Understand

Naturalness arguments imply the existence of higgsinos lighter than 200-300 GeV.

• However, because these higgsinos are nearly mass degenerate, they release very little visible energy in their decays, and (even putting aside triggering issues) signals from electroweak higgsino pair production typically remain buried under Standard Model backgrounds.
• Prospects for detecting higgsino pair production via events with monojets or mono-photons from initial state radiation are also bleak because of signal-to-background rates typically at the 1% level.
• Here, we consider the possibility of reducing backgrounds by requiring the presence of soft daughter leptons from higgsino decays in monojet events.