Speaker
Description
A recent analysis for long-lived particles using data collected by the ATLAS detector at the LHC is presented. The analysis uses vertices reconstructed from track segments in the muon spectrometers to search for long-lived particle decays displaced up to 14m from the primary interaction vertex. The results are interpreted in terms of scalar-portal and Higgs-boson-portal baryogenesis models. A dedicated analysis channel is employed to include models which produce long-lived particles in association with prompt Z-bosons, providing sensitivity to axion-like particle and dark photon models. The use of a single displaced vertex significantly increases the sensitivity to longer and shorter lifetimes with respect to the previous ATLAS search using two displaced vertices, extending the sensitivity to decay lengths ranging from 5 cm to 40 m.