Search for electroweak production of supersymmetric states in scenarios with compressed mass spectra at sqrt(s)=13 TeV with ATLAS

Dark matter coannihilation via species with only electroweak interactions is generically realised in the MSSM. Key benchmarks include a Higgsino-dominated LSP, or a bino LSP coannihilating with winos or sleptons that are nearby in mass. Hadron collider probes of these compressed scenarios are only recently surpassing nearly two-decade-old LEP limits. A search strategy is presented that opens new sensitivity to these challenging regimes using an ISR boost and soft lepton reconstruction down to 4 GeV - among the lowest used by ATLAS.