Speaker
Description
Supersymmetry, which extends the Standard Model (SM) by introducing supersymmetric partners for the SM particles, can provide an elegant solution to the hierarchy problem. One of the most important parameters in supersymmetry is the mass of the supersymmetric partner to the top quark, referred to as stop. In the absence of the stop signature in the previous searches at the LHC, compressed stop searches in which the mass of the stop is close to the mass of the lightest neutralino become more important. In the compressed scenarios, the momentum transfer to decay products of the stop tend to be low, possibly a few GeV. Hence, the identification and reconstruction of those ``soft'' objects can play a crucial role in the searches. In this talk, 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.
