An optimization of jet reconstruction for the Matrix Element Method in semileptonic $ttH(bb)$ search using the ATLAS detector

Run 2 of the LHC is probing physics at the TeV scale through pp collisions with centerof-mass energy $\sqrt{s}$ = 13 TeV at unprecendented luminosities. One particular process that this promises to shed light on is the production of the Higgs boson in association with top quarks, $ttH(b\bar{b})$. This report studies the reconstruction of jets from W boson decay in the $ttH(b\bar{b})$ process. An algorithm to improve the reconstruction efficiency of the jets from W boson decay by recognizing their kinematic properties and applying specific requirements is introduced, implemented, and its effects are studied. The altered algorithm is shown to improve the separation between signal and background of the MEM calculations between 15% − 25%. The algorithm offers to potentially decrease the uncertainties in the calculated signal strength of the $ttH(b\bar{b})$ process.