Search for 3rd generation SUSY particles with the ATLAS experiment at the Large Hadron Collider

The ATLAS limits on the production of third generation squarks are already setting tight constraints to the existent of low fine-tuning supersymmetry configurations. However, the sensitivity to such particles is at the moment significant weaker if their mass is very similar to the sum of the masses of the particles they decay into. In this configuration, b-quarks emitted in the third generation squark decays tend to be very soft, and their identification becomes extremely challenging.

The ATLAS sensitivity to such compressed scenarios can be enhanced by developing discriminants that are sensitive to the presence of additional secondary vertices in the event, regardless of whether they can be associated to jets. The aim of this project is to define this discriminant and apply it to searches of stops and sbottoms using the full ATLAS Run 2 dataset.