Dark sector @ ATLAS and CMS

The SM of Particle Physics is the model that, up to now, best describes the matter content and its fundamental interactions. Though the tests it has gone through during the past years have always proven to confirm its validity, it still cannot provide answers for some fundamental questions, such as the nature of dark matter or the matter-antimatter asymmetry. Therefore, since the start of their physics program, large experiments such as the ones based at the LHC, like ATLAS and CMS, have looked for hints of BSM Physics. Among these kind of attempts, of particular interests are so-called Dark Sector searches, where the existence of a whole new sector of particles, governed by new interactions, is looked for. These searches present challenges in terms of (offline and online) reconstruction, background estimation and modelling, as they provide a very rich and unconventional phenomenology. This article reviews the most recent Dark Sector searches performed by the ATLAS and CMS collaboration, with particular focus on Dark Sector models involving the existence of a dark QED or dark QCD. Specific challenges met by the different searches are highlighted and plans to overcome them in the next LHC runs are illustrated.