Differential and $CP$ measurements in $ttH/tH (H→bb)$ with $ATLAS$

The Higgs-boson production in association with top-quarks is a direct probe of the Higgs interaction with top-quark and allows to constrain the charge-parity ($CP$) of top-Higgs coupling. The Higgs boson decay into two $b$-quarks has the highest branching ratio and allows in principle for the kinematic reconstruction of the Higgs boson, although the high $b$-jet multiplicity due to the additional top quark decay products require dedicated analysis strategies based on machine-learning. The $CP$ nature is studied via $CP$-sensitive observables that are built using top quark variables. The talk will present the most recent results on the differential measurement of this production and measurement of the $CP$-mixing angle in the $ttH(H->bb)$ channel using the $ATLAS$ full Run-2 dataset.