Electroweak superpartners scrutinized at the LHC in events with multi-leptons

We analyze a multi-lepton signal plus missing transverse energy from neutrinos expected at the LHC for abino-like neutralino as the lightest supersymmetric particle (LSP), when the left sneutrino is the next-to-LSP and hence a suitable source of binos. The discussion is carried out in the framework of the mu vSSM, where the presence of R-parity violating (RPV) couplings involving right-handed neutrinos solves the problem and can reproduce simultaneously the neutrino data. Left sneutrinos/sleptons are pair-produced at pp collisions decaying to binos, with the latter decaying via RPV to Wl or Zv. This signal can be compared with LHC searches for electroweak superpartners through chargino-neutralino production. The reduced cross section of the sneutrino/slepton production in comparison with the one of the latter process, limits the sensitivity of the searches to small sneutrino/slepton masses. Although the resulting compressed spectrum typically evades the aforementioned searches, we show that analyses using recursive jigsaw reconstruction are sensitive to these scenarios. As a by-product, we find that the region of bino masses 110-120 GeV and sneutrino masses 120-140 GeV can give rise to a tri-lepton signal compatible with the local excess recently reported by ATLAS. (C) 2019 The Author(s). Published by Elsevier B.V.