Supersymmetric crevices: Missing signatures ofR-parity violation at the LHC

Abstract

Supersymmetry is under pressure from LHC searches requiring colored superpartners to be heavy. We demonstrate $R$-parity violating (RPV) spectra for which the dominant signatures are not currently well searched for at the LHC. In such cases, the bounds can be as low as 800 GeV on both squarks and gluinos. We demonstrate that there are nontrivial constraints on squark and gluino masses with baryonic RPV ($UDD$ operators) and show that in fact leptonic RPV can allow comparable or even lighter superpartners. The constraints from many searches are weakened if the LSP is significantly lighter than the colored superpartners, such that it is produced with high boost. The LSP decay products will then be collimated, leading to the miscounting of leptons or jets and causing such models to be missed even with large production cross-sections. Other leptonic RPV scenarios that evade current searches include the highly motivated case of a Higgsino LSP decaying to a tau and two quarks, and the case of a long-lived LSP with a displaced decay to electrons and jets. The least constrained models can have SUSY production cross-sections of $\ensuremath{\sim}\mathrm{pb}$ or larger, implying tens of thousands of SUSY events in the 8 TeV data. We suggest novel searches for these signatures of RPV, which would also improve the search for general new physics at the LHC.