Search for long-lived particles with multijet displaced vertices in proton-proton collisions at sqrt(s)=13 TeV

Results are reported from a search for long-lived exotic particles in proton-proton collision events collected by the CMS experiment at a center-of-mass energy of $\sqrt{s}=13$~TeV. The data sample, which was collected during 2015 and 2016, corresponds to an integrated luminosity of 38.5~fb$^{-1}$. This search uses benchmark signal models in which long-lived neutralinos or gluinos are pair-produced and each decay into two or more quarks, leading to a signal with multiple jets and two displaced vertices composed of many tracks. No events with two well-separated high-track-multiplicity vertices are observed, and limits are placed on the pair production cross section as a function of mass and lifetime of the long-lived particle. At 95\% confidence level, the analysis excludes cross sections above approximately 0.3~fb for neutralinos or gluinos with mass between 800 and 2600~GeV and mean proper decay length between 1 and 40~mm. Gluino masses are excluded below 2200~GeV for mean proper decay lengths between 0.8 and 80~mm.