2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37996Using the CLEO-II detector at the CESR $e^+e^-$ storage ring running at the center-of-mass energy around 10.6 GeV, we have studied exclusive production of charmonium states in two-photon collisions. Employing a dataset comprising 3.0 ${\rm fb}^{-1}$ we have searched for decays of the $η_c$, $χ_{c0}$ and $χ_{c2}$ mesons resulting in four charged hadrons. We report on the measurements of the cross sections and two-photon widths of these charmonium states.7 pages, uses psfig.tex, 5 eps figures appended at the endHigh Energy Physics - ExperimentHigh Energy Physics - Phenomenologytext