Search for long-lived, massive particles in events with displaced vertices and missing transverse momentum in $\sqrt{s}=13\text{}\text{}\mathrm{TeV}$ $pp$ collisions with the ATLAS detector

A search for long-lived, massive particles predicted by many theories beyond the Standard Model is presented. The search targets final states with large missing transverse momentum and at least one high-mass displaced vertex with five or more tracks, and uses $32.8\text{}\text{}{\mathrm{fb}}^{-1}$ of $\sqrt{s}=13\text{}\text{}\mathrm{TeV}$ $pp$ collision data collected by the ATLAS detector at the LHC. The observed yield is consistent with the expected background. The results are used to extract 95% C.L. exclusion limits on the production of long-lived gluinos with masses up to 2.37 TeV and lifetimes of $O\left({10}^{-2}\right)-O\left(10\right)\text{}\text{}\mathrm{ns}$ in a simplified model inspired by split supersymmetry.