Soft Supersymmetry Searches at ATLAS and CMS

Soft supersymmetry (SUSY) searches that target models with compressed mass spectra are highly motivated by theoretical considerations, such as naturalness or dark matter relic constraints. This paper gives a concise overview of the most recent results from the ATLAS and CMS Experiments that target soft SUSY signatures, with a focus on the underlying analysis tools and techniques that allow these regions of phase space to be probed. These include sophisticated analysis methods ranging from the identification of soft objects and initial state radiation jets, to specific experimental observables, such as Recursive Jigsaw Reconstruction variables. Improved triggering techniques are also instrumental in expanding the accessible phase space. Different theoretical models are considered, involving strong, electroweakino and vector-boson fusion production, as well as a soft hadronically-decaying tau model. The presented searches are based on proton-proton collisions data from Run II of the Large Hadron Collider, recorded with the ATLAS and CMS detectors at a centre-of-mass energy $\sqrt{s} = {13~\mathrm{TeV}}$, corresponding to integrated luminosities ranging from $35.9~{\mathrm{fb}^{-1}}$ to $139~{\mathrm{fb}^{-1}}$.