Studies of C-jet spectra in various Flavor Schemes for $\bar{t}t+c$ cross section measurement by the ATLAS Detector

The analysis uses LHC proton-proton collision data at the center-of-mass energy $\sqrt{s}=13\ TeV$ with an integrated luminosity of $139\ fb^{-1}$ collected with the ATLAS detector in 2015-2018. A comparison of three flavor scheme, four flavor scheme and five flavor scheme has been performed using top quark pair-production with additional charm jet ( $\bar{t}t+c$) events simulated by MadGraph and showered by Pythia8. Spectra of additional c-jets that do not originate from the top quark decay are compared in the three schemes. These studies are motivated by the upcoming $\bar{t}t+c$ jets cross section measurement. No significant differences in spectra of additional c-jets are observed in the different flavor schemes.