Search for pair-produced multijet resonances using data scouting

Searches for pair-produced multijet signatures are presented. The analyses use a data sample corresponding to an integrated luminosity of $128~\mathrm{fb}^{-1}$ of proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ to measure the average mass distributions of pairs of tri-jets, both merged and resolved, and pairs of merged dijets. The data were collected using data scouting, which saves events with trigger-level reconstruction, enabling the recording of events corresponding to relatively low multi-jet masses. The results are interpreted within an R-parity violating supersymmetric framework in which the pair productions of higgsinos, gluinos, and top squarks are used as benchmark models. Decays to three resolved jets, as well as to highly Lorentz-boosted pairs of two or three quarks yielding single large radius jets, are considered. The search excludes RPV gluinos with mass less than 1.7 TeV, and extends prior exclusions of RPV squarks and gluinos to the low mass region between 70 and 200 GeV. The electroweak production of R-parity violating supersymmetry is probed for the first time in fully hadronic final states, yielding the first exclusions on prompt hadronically decaying mass-degenerate higgsinos.