Exclusive Production of Quarkonia in $pp$ and $p \bar p$ Collisions Far from the Threshold

Abstract

I discuss exclusive production of the $\eta'$, $J/\psi$, and $\chi_c(0^+)$ mesons in $pp$ and $p \bar p$ collisions at high energies. QCD diffractive mechanisms as well as nondiffractive mechanisms are discussed. Different unintegrated gluon distribution functions (UGDF) are used. Some differential distributions are shown and discussed.