Central exclusive production of $\eta_c$ and $\chi_{c0}$ in the light-front k$_{\perp}$-factorization approach

TL;DR

This paper investigates the exclusive production of specific charmonium states in proton-proton collisions at LHC energies, highlighting the importance of nonperturbative gluon contributions and employing unintegrated gluon distribution models.

Contribution

It presents the first analysis of the $pp o pp\,\eta_c$ reaction and incorporates nonperturbative gluon effects using color dipole-based unintegrated gluon distributions.

Findings

Nonperturbative gluon contributions are significant for $\,\eta_c$ production.

First study of $pp o pp\eta_c$ at LHC energies.

Models based on color dipole cross-section improve nonperturbative region description.

Abstract

We study the exclusive production of $J^{PC}=0^{++}, 0^{--}$ charmonium states in proton-proton collisions at the LHC energies The $pp \to pp\eta_c$ reaction is discussed for the first time. We observe a substantial contribution from the nonperturbative domain of gluon virtualities, especially for $\eta_c$ production. To model the nonperturbative region better, we utilize models of the unintegrated gluon distribution based on parametrizations of the color dipole cross-section.