Search for single production of vectorlike top partners through th channel at the HE-LHC and FCC-hh

Abstract

The vectorlike top partners are potential signature of some new physics beyond the Standard Model at the TeV scale. In this paper, we propose to search for the vectorlike T quark with charge 2/3 in the framework of a simplified model where the top partners only couples with the third generation of Standard Model quarks. We investigate the observability for electroweak production of a vectorlike T quark in association with a standard model bottom quark through the process $pp\to T\overline{b}j$ with the subsequent decay mode of $T\to t(\to b{W}^{+}\to b{\ell }^{+}{\nu }_{\ell })h(\to \gamma \gamma )$, at the proposed High Energy Large Hadron Collider (HE-LHC) and Future Circular Collider in hadron-hadron mode (FCC-hh) including the realistic detector effects. The 95% confidence level excluded regions and the $5\sigma$ discovery reach in the parameter plane of ${\kappa }_T-m_T$, are respectively obtained at the HE-LHC with the integrated luminosity of 15 ab${}^{-1}$ and the FCC-hh with the integrated luminosity of 30 ab${}^{-1}$. We also analyze the projected sensitivity in terms of the production cross section times branching fraction at the HE-LHC and FCC-hh.