Single production of a vector-like top as a probe of charged higgs bosons at a muon–proton collider

Abstract We investigate the discovery potential of a vector-like top partner ( T ) in the Type-II Two-Higgs-Doublet Model at a high-energy $$\mu p$$ μ p collider through the charged-Higgs cascade $$\mu ^+ p \rightarrow \nu _\mu \,{\bar{b}} T \rightarrow \nu _\mu \,{\bar{b}} H^+ b$$ μ + p → ν μ b ¯ T → ν μ b ¯ H + b with $$H^+\rightarrow t{\bar{b}}$$ H + → t b ¯ . The signal is characterized by four b jets, one charged lepton, and missing transverse energy. A detector-level analysis is performed for representative spectra with $$m_{H^\pm }\simeq 600$$ m H ± ≃ 600 –650 GeV and $$m_T\simeq 1.2$$ m T ≃ 1.2 –1.9 TeV. We find that a $$5\sigma $$ 5 σ discovery is achievable for $$m_T\simeq 1.2$$ m T ≃ 1.2 TeV at integrated luminosities of 100 and $$150~\textrm{fb}^{-1}$$ 150 fb - 1 even in the presence of $$20\%$$ 20 % background systematics. For $$m_T\simeq 1.5$$ m T ≃ 1.5 TeV, discovery remains possible for vanishing or moderate systematics, while heavier benchmarks require larger statistics and/or improved control of backgrounds.