https://doi.org/10.1140/epjc/s10052-016-3917-z
Regular Article - Theoretical Physics
Probing the gluon density of the proton in the exclusive photoproduction of vector mesons at the LHC: a phenomenological analysis
1
Department of Astronomy and Theoretical Physics, Lund University, 223-62, Lund, Sweden
2
Instituto de Física e Matemática, Universidade Federal de Pelotas, Caixa Postal 354, 96010-900, Pelotas, RS, Brazil
* e-mail: barros@ufpel.edu.br
Received:
17
November
2015
Accepted:
1
February
2016
Published online:
24
February
2016
The current uncertainty on the gluon density extracted from the global parton analysis is large in the kinematical range of small values of the Bjorken-x variable and low values of the hard scale 
. An alternative to reduces this uncertainty is the analysis of the exclusive vector meson photoproduction in photon–hadron and hadron–hadron collisions. This process offers a unique opportunity to constrain the gluon density of the proton, since its cross section is proportional to the gluon density squared. In this paper we consider current parametrisations for the gluon distribution and estimate the exclusive vector meson photoproduction cross section at HERA and LHC using the leading logarithmic formalism. We perform a fit of the normalisation of the 
cross section and the value of the hard scale for the process and demonstrate that the current LHCb experimental data are better described by models that assume a slow increasing of the gluon distribution at small x and low .
© The Author(s), 2016
