Search for Higgs boson production in association with a pair of top-quarks with the Atlas detector

A great success of the Standard Model (SM) was the discovery of a Higgs boson in 2012. Measuring its properties and yet unobserved production and decay modes provides a test of the validity of the SM. The process of Higgs production in association with a pair of top-quarks ($t\bar{t}H$) is still unobserved. Further interest arises from the fact that it provides direct access to the top Yukawa coupling which is possibly sensitive to new physics and therefore provides a crucial test of the SM. In order to maximize the statistics of the data sample of the $t\bar{t}H$ process the final state of the Higgs decay with the highest branching ratio into a pair of $b$-quarks has been chosen for this search. This summary is based on the recently published results using $36.1 fb^{-1}$ in pp collisions collected with the Atlas detector in 2015 and 2016. Especially the reconstruction techniques to correctly match the jets originating from $b$-quarks to their origin, are reviewed. The measurement in the $t\bar{t}H(b\bar{b})$ final state is put in context with the combination of the other Higgs decay modes, resulting in evidence for this process.