Long-lived biνo at the LHC

We examine the detection prospects for a long-lived bi nu o, a pseudo-Dirac bino which is responsible for neutrino masses, at the LHC and at dedicated long-lived particle detectors. The bi nu o arises in U(1)(R)-symmetric supersymmetric models where the neutrino masses are generated through higher dimensional operators in an inverse seesaw mechanism. At the LHC the bi nu o is produced through squark decays and it subsequently decays to quarks, charged leptons and missing energy via its mixing with the Standard Model neutrinos. We consider long-lived bi nu os which escape the ATLAS or CMS detectors as missing energy and decay to charged leptons inside the proposed long-lived particle detectors FASER, CODEX-b, and MATHUSLA. We find the currently allowed region in the squark-bi nu o mass parameter space by recasting most recent LHC searches for jets+ . We also determine the reach of MATHUSLA, CODEX-b and FASER. We find that a large region of parameter space involving squark masses, bi nu o mass and the messenger scale can be probed with MATHUSLA, ranging from bi nu o masses of 10 GeV-2 TeV and messenger scales 10(2-11) TeV for a range of squark masses.