Search for pair production of vector-like quarks in the Wb+X final state using the full Run 2 dataset of $pp$ collisions at $\sqrt{s}=$ 13 TeV from the ATLAS detector

Vector-like quarks (VLQ) are predicted in many extensions to the Standard Model (SM), especially those aimed at solving the hierarchy problem. Their vector-like nature allows them to extend the SM while still being compatible with electroweak sector measurements. In many models, VLQs decay to a SM boson and to a third-generation quark. Pair production of VLQ provides a model-independent method of searching due to the quantum chromodynamics production of the particles. This talk presents a search for pair production of vector-like top quarks that each decays into a SM W boson and a bottom quark, with one W boson decaying leptonically and the other decaying hadronically. The analysis takes advantage of boosted boson identification and a data-driven correction of the dominant $t\bar{t}$ background prediction to improve sensitivity. Furthermore, this analysis extends the previous analysis sensitivity by including the full Run 2 ATLAS dataset.