  Long-lived particles can manifest themselves at the LHC via "displaced
vertices" - several charged tracks originating from a position separated from
the proton interaction point by a macroscopic distance. Here we demonstrate a
potential of the muon trackers at the CMS experiment for displaced vertex
searches. We use heavy neutral leptons and Chern-Simons portal as two examples
of long-lived particles for which the CMS muon tracker can provide essential
information about their properties.
