Can R-parity violation hide vanilla supersymmetry at the LHC?
  Current experimental constraints on a large parameter space in supersymmetric models rely on the large missing energy signature. This is usually provided by the lightest neutralino which stability is ensured by the R-parity. However, if the R-parity is violated, the lightest neutralino decays into the standard model particles and the missing energy cut is not efficient anymore. In particular, the UDD type R-parity violation induces the neutralino decay to three quarks which potentially leads to the most difficult signal to be searched at hadron colliders. In this paper, we study the constraints on the R-parity violating supersymmetric model using a same-sign dilepton and a multijet signatures. We show that the gluino and squarks lighter than a TeV are already excluded in constrained minimal supersymmetric standard model with R-parity violation if their masses are approximately equal. We also analyze constraints in a simplified model with R-parity violation. We compare how R-parity violation changes some of the observables typically used to distinguish a supersymmetric signal from standard model backgrounds. 
Masaki Asano, Krzysztof Rolbiecki, Kazuki Sakurai
hep-ph hep-ex