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

¹ Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Kraków, Poland
² College of Mathematics and Natural Sciences, University of Rzeszów, ul. Pigonia 1, PL-35-310 Rzeszów, Poland

^* e-mail: izabela.babiarz@ifj.edu.pl
^** e-mail: wolfgang.schafer@ifj.edu.pl
^*** e-mail: antoni.szczurek@ifj.edu.pl

Published online: 16 February 2024

Abstract

Abstract. The charmonium state η_c is a pseudoscalar meson (J^PC = 0⁻⁺). We will review the proton-proton and electron-ion reactions, where η_c 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.