Long-lived higgsinos as probes of gravitino dark matter at the LHC

Abstract

We investigate the LHC sensitivity to supersymmetric models with light higgsinos, small R-parity breaking and gravitino dark matter. The limits on decaying gravitino dark matter from gamma-ray searches with the Fermi-LAT put a lower bound on the higgsino-like neutralino NLSP decay length, giving rise to a displaced-vertex collider signature. Using publicly available tools for simulation of signal, background and detector response, we find that higgsinos with masses of 100 - 400 GeV and R-parity violation of ζ ∼ 10 -8 - 10-9 can show up in the 8 TeV LHC data with 10 - 30 fb-1 of integrated luminosity. We demonstrate that in the case of a signal, the higgsino mass can be determined by reconstruction of the dimuon mass edge. © 2013 SISSA.