  Single diffractive dissociation (SDD) of nucleon in high-energy proton-proton
and proton-antiproton collisions is considered in terms of a simple two-Reggeon
model with nonlinear Regge trajectories. It is demonstrated that the
$f$-Reggeon impact on the corresponding cross-sections is not negligible up to
the LHC energies. As well, it is shown that the account of the $f$-Reggeon
exchanges allows to describe the elastic diffractive scattering (EDS) and SDD
of nucleons at ultrahigh energies in the framework of a unified
phenomenological scheme. The predictive value of the proposed model is
verified.
