Coherent photoproductions of $J/\Psi$ and $\Upsilon$ mesons in pp and PbPb ultraperipheral collisions from dynamical gluon distribution

TL;DR

This paper calculates the coherent photoproduction of $J/$ and $$ mesons in pp and PbPb ultraperipheral collisions using a dynamical gluon distribution model, comparing results with experimental data to validate the approach.

Contribution

It introduces the use of a dynamical gluon distribution with GLR-MQ-ZRS modifications for meson photoproduction calculations, showing improved agreement with high-energy experimental data.

Findings

Dynamical gluon distribution fits high-energy meson photoproduction data.

Model agrees well with experimental results at large rapidity.

Provides insights into nuclear modifications and corrections of DGLAP equations.

Abstract

We present calculations of coherent photoproduction of vector mesons ($J/\Psi$ and $\Upsilon$) with leading-order parton distribution functions to check new kinds of corrections of the DGLAP equations and nuclear modifications. The input gluon distribution of the proton is the dynamical parton model from the DGLAP equations with GLR-MQ-ZRS (Gribov-Levin-Ryskin, Mueller-Qiu, Zhu-Ruan-Shen) modifications. From comparison between several other gluon distribution models, we find that the dynamical gluon distribution fits with the results of meson photoproduction experiments in the high energy region. The calculation of the differential cross sections using dynamical and other gluon distributions is compared with the experimental data from the HERA, ZEUS and LHCb Collaborations. Although there is little data for the rapidity distribution of vector meson photoproduction near zero rapidity, the dynamical gluon distribution works well with the data in the large rapidity region.