Overview of searches, prospects, what are we missing?

Abstract

Feebly interacting particles (FIP) are present in many scenarios of physics beyond the Standard Model. The physics from the FIP can have different imprints in the phenomenology as dark matter, heavy neutral leptons, long-lived particles, axion-like particles, dark showers, etc. It is a vast landscape to explore, however, LHC experiments have currently several searches that try to cover the different signatures that FIP present. The coverage of ATLAS and CMS during the first runs have been very successful. Run 3 looks promising since more data will be acquired and new identification techniques will be applied. However, technical improvements are not enough to cover all the possibilities, new strategies and proposals are necessary to make real progress in the understanding of the nature of FIPs.