Search for events with two displaced vertices from pair-produced neutral long-lived particles decaying to hadronic jets in the muon spectrometer of the ATLAS detector with full Run 2 data

This analysis is a search for events with two displaced vertices reconstructed from the decay of pair-produced neutral, weakly-interacting, long-lived particles using the muon spectrometer of the ATLAS detector. The search uses a model-independent strategy and employs a custom trigger for reconstructing displaced hadronic jets in the muon spectrometer with 139 fb-1 of p-p collision data at √s = 13 TeV collected in Run 2. The results are interpreted in terms of a Higgs scalar portal model, which probes the existence of a hidden sector that weakly couples to the standard model. This analysis provides one of the first LHC explorations of models of neutral naturalness, which are generic extensions to hidden valley portal models. The search observed 0 events in the signal region, which is compatible with the expected background of 0.32 ±0.05 events. Limits were set on long-lived particle lifetime for all simulated signal mass points.