Pursuit of new phenomena in final states with high jet multiplicity, high jet masses and missing transverse momentum with ATLAS at $\sqrt{s} = 13$ TeV

Results are reported of a search for new phenomena --- such as supersymmetric particle production --- that could be observed in high-energy proton-proton collisions. Events with large numbers of jets, together with missing transverse momentum from unobserved particles, are selected. The data analysed were recorded by the ATLAS experiment during 2015 and early 2016 using the 13 TeV centre-of-mass proton-proton collisions at the Large Hadron Collider, and correspond to an integrated luminosity of $18.2\,\mathrm{fb}^{-1}$. The search selects events with various jet multiplicities from $\ge8$ up to $\ge 10$ jets, and with various requirements on the sum of masses of large-radius reclustered jets. No excess above Standard Model expectations is observed. The results are interpreted within two supersymmetry models, where gluino masses up to 1600 GeV are excluded at 95% confidence level, extending previous limits.