Search for heavy scalars with flavour-violating couplings in multi-lepton and multi-b-jets final states

Several extensions of the Standard Model predict a second complex Higgs doublet. The corresponding additional scalars can exhibit flavour changing neutral currents, while in the alignment limit the SM Higgs properties are unaffected. This poster presents the results of a search for new scalar particles featuring flavour-violating couplings in the quark sector, in the multi-lepton and multi-b-jet final state. Various 2HDM signal production and decay modes are considered, including uncommon three-top and same-sign top final states. Events are categorised depending on the multiplicity of light leptons (electron and muon) and a DNN-based categorisation to enhance the purity of each 2HDM signal. The Monte Carlo predictions of the dominant background processes are corrected and validated using dedicated control and validation regions. Finally, dedicated DNN are trained to discriminate signal from background in each of the signal categories and are used as final discriminants in the fit.