Searches for direct pair production of third generation squarks with the ATLAS detector

Naturalness arguments for weak-scale supersymmetry favor supersymmetric partners of the third generation quarks with masses light enough to be produced at the LHC. The ATLAS experiment has a variety of analyses devoted to stop direct production exploiting advanced analysis techniques. In the compressed stop scenarios, the momentum transfer to decay products of the stop tend to be low, possibly a few GeV. Hence, the identification and reconstruction of these “soft” objects can play a crucial role in the searches. In this article, recent result from the compressed stop searches in $pp$ collisions at $\sqrt{s}$ =13 TeV with the ATLAS detector and new developments for soft b-hadron tagging techniques are presented.