Signatures of heavy Majorana neutrinos and DESY HERA’s isolated lepton events

The graph of neutrinoless double beta decay is applied to DESY HERA data and generalized to final states with any two charged leptons. Considered is the case in which one of the two escapes typical identification criteria and the case when a produced tau decays hadronically. Both possibilities give one isolated lepton with high transverse momentum, hadronic activity, and an imbalance in transverse momentum. We examine the kinematical properties of these events and compare them with the high $p_T$ isolated leptons reported by the H1 Collaboration. Their positive charged muon events can be explained by the “double beta” process and we discuss the possibilities for the precise determination which original final state produced the single isolated lepton. To confirm our hypothesis one should search in the data for high pseudorapidity and/or low $p_T$ leptons or for additional separated jets.