Abstract (data
abstract)
CERN-LHC. A search for hadronic decays of neutral, weakly interacting, long-lived particles in proton-proton collisions at a centre-of-mass energy of 13 TeV is presented. The data sample used, collected during 2015+2016 ATLAS data-taking period, has a total integrated luminosity of 36.1 fb$^{-1}$. The analysis searches for events with two displaced vertices in the MS, or one displaced vertex in the MS in association with additional activity in the detector that improves the sensitivity for longer lifetimes. Three separate strategies are studied, defined by the number of MS vertices and additional selection criteria. The observed numbers of events are consistent with the expected background and limits for several benchmark signals are determined.