EPS Poster : Search for SUSY top squarks in final states with a hadronically decaying t, c and large missing ET

a search top-squark pair production, in minimal flavour violating supersym- metry models, in final states with a top quark, charm quark and missing transverse momentum using a dataset collected with the ATLAS detector during LHC Run 2, corresponding to a integrated luminosity of 139 fb at a centre-of-mass energy of 13 TeV collisions. The analysis is motivated by a search of a non-minimal flavour violation in the 2nd and 3rdgeneration squark sector of an extended MSSM model. The top squark in these models hastwo possible decay modes, either t ̃ → c χ ̃10 or t ̃ → t χ ̃10. The analysis is optimised assumingboth decay modes are equally probable, leading to the most likely final state of tc + ET miss. Generally good agreement is found between the post-fit SM expectation and the data in the search regions, however some search regions possess 2σ excesses over the SM prediction. Limits are presented in the m(t ̃) vs m( χ ̃10) plane and, in addition, limits on the BR(t ̃ → t χ ̃10) as a function of the m(t ̃) are also produced. Top-squark masses of up to 800 GeV are excluded for scenarios with light neutralinos, and top-squark masses up to 600 GeV are excluded in scenarios where the neutralino and top squark are almost mass degenerate.