Search for lepton number violation and other exotic processes at NA62

NA62 is a fixed target experiment at CERN, with the main goal of measuring the branching ratio of the very rare decay K+ → π+νν¯. However, the wide physics program covered by the experiment allows the search for other possible indications of new physics beyond the Standard Model. In this document, the searches for lepton number violation and invisible vector bosons (“dark photon”) are reported