Exclusive vector-toponium photoproduction in hadronic collisions

An exploratory study of the exclusive production of a vector - toponium ${\psi }_t$ state by photon - hadron interactions is performed considering proton - proton and proton - nucleus collisions at the Large Hadron Collider (LHC) and Future Circular Collider (FCC) energies. The scattering amplitude is calculated using the $k_T$ - factorization formalism assuming that the vector - toponium state can be described by a Gaussian light-cone wave function and considering different models for the unintegrated gluon distribution. Predictions for the rapidity distributions and total cross - sections are presented. Our results indicate that the experimental measurement of this final state will be very difficult for the expected integrated luminosities at the LHC and FCC.