ηc production within light-cone approach in pp and eA collisions

Abstract. The charmonium state ηc is a pseudoscalar meson (JPC = 0−+). We will review the proton-proton and electron-ion reactions, where ηc can be produced through the fusion of two virtual gluons in pp collision or one virtual photon-one real photon in eA collision. The main ingredient in our light-cone approach is the space-like transition form factor with dependence on two virtu-alities of the particles. The idea is to construct the form factor based on the wave function of the cc¯ state. The radial part of the wave function can be found by solving the Schrödinger equation. The transformation to the light-cone variable is performed using the Terentev prescription. We present the effects of the so-obtained form factors in the context of electron-ion collisions. Future facilities such as EIC or LHeC give the opportunity to probe the form factor dependence on the virtuality in e−A collisions. Our results indicate that the electron-ion colliders can be considered as an alternative and provide supplementary data to those obtained in e+e− colliders.