Search for supersymmetry in the single-lepton final state using the sum of large jet masses

A search is described for supersymmetric particles in proton-proton collisions in the final state with a single, high transverse momentum lepton; multiple jets, including at least one b-tagged jet; and large missing transverse momentum. The search uses the complete Run 2 dataset of proton-proton collisions at √s = 13 TeV collected by the CMS experiment from 2016 to 2018, corresponding to a total integrated luminosity of 136 ifb. The search focuses on processes leading to high jet multiplicities, such as gluino pair production with g->ttχ. The quantity M_J, defined as the sum of the masses of the large-radius jets in the event, is used in conjunction with other kinematic variables to provide discrimination between signal and background and as a key part of the background estimation method. The analysis is sensitive to models of supersymmetry with gluino pair production followed by three-body decays into top quarks and neutrinos. The search also probes models with two-body gluino decays producing on-shell top squarks.