Search for vector-like quarks

Vector-like quarks (VLQ) are predicted by many extensions of the Standard Model. If the Higgs sector is not changed the VLQs can be isospin singlets, doublets or triplets, and can decay via charged ($W$) or neutral currents ($\textit{H, Z}$). A search for pair-production of vector-like quarks $\textit{T}$ and $\textit{B}$ with a leptonically decaying $\textit{Z}$ boson will be presented, with 36.1 fb$^{-1}$ of data collected by the ATLAS detector at the Large Hadron Collider at $\sqrt{s} = 13$ TeV. This search targets events that contain a pair of opposite-sign same-flavour leptons, and at least a third generation quark, which would arise from the VLQ decay. The lepton pair is selected to form a $\textit{Z}$ candidate, with the boosted regime being explored in order to target high VLQ masses.