The Standard Model (SM) of particle physics is currently the best theory for describing elementary particles and their interactions, but there are several problems and open questions related to it. For instance it does not incorporate gravity, and it does not explain dark matter, hence there is a need for new fundamental theories of nature beyond the current theory. A theory that addresses some of the problems with the SM is Supersymmetry, as a symmetry between fermions and bosons, which predicts a superpartner for each SM particle.
Here we present a search for direct production of sleptons, which are the supersymmetric partners of the leptons. The sleptons are assumed to decay to leptons and neutralinos, where the latter is considered to be a good dark matter candidate particle. The data set used in the analysis consists of an integrated luminosity of 36.1 1/fb from proton-proton collisions at 13 TeV centre-of-mass energy collected by the ATLAS experiment at the Large Hadron collider at CERN in 2015 and 2016. No significant excess above the expected Standard Model background is observed.