Probing TeV scale top-philic resonances with boosted top-tagging at the high luminosity LHC

We investigate the discovery potential of singly produced top-philic resonances at the high luminosity (HL) LHC in the four-top final state. Our analysis spans over the fully hadronic, semileptonic, and same-sign dilepton channels where we present concrete search strategies adequate to a boosted kinematic regime and high jet-multiplicity environments. We utilize the template overlap method with newly developed template observables for tagging boosted top quarks, a large-radius jet variable MJ, and customized b-tagging tactics for background discrimination. Our results show that the same-sign dilepton channel gives the best sensitivity among the considered channels, with an improvement of significance up to 10%-20% when combined with boosted top-tagging. Both the fully hadronic and semileptonic channels yield comparable discovery potential and contribute to further enhancements in the sensitivity by combining all channels. Finally, we show the sensitivity of a top-philic resonance at the LHC and HL-LHC by showing the 2σ exclusion limit and 5σ discovery reach, including a combination of all three channels.