Probing the gluon density of the proton in the exclusive photoproduction of vector mesons at the LHC: A phenomenological analysis

Abstract

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 $Q^2$. 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 parametrizations 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 normalization of the $\gamma h$ 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 $Q^2$.

8 pages, 6 figures, 1 table. Version published in European Physical Journal C

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Cited by in corpus (11)

• BFKL evolution and the growth with energy of exclusive J/Psi and Upsilon photo-production cross-sections
• Dynamical parton distributions from DGLAP equations with nonlinear corrections
• Double vector meson production in photon - hadron interactions at hadronic colliders
• Mapping the dominant regions of the phase space associated with $c\bar{c}$ production relevant for the Prompt Atmospheric Neutrino Flux
• Exclusive photoproduction of vector meson at next-to-leading order from Color Glass Condensate
• Semiexclusive production of $J/\psi$ mesons in proton-proton collisions with electromagnetic and diffractive dissociation of one of the protons
• Exclusive vector meson production with a leading neutron in photon - hadron interactions at hadronic colliders
• Stability of Gluonic Systems with Multiple Soft Interactions
• Exclusive vector meson photoproduction with a leading baryon in photon - hadron interactions at hadronic colliders
• Coherent photoproductions of $J/\Psi$ and ${\rm Y}$ mesons in pp and PbPb ultraperipheral collisions from dynamical gluon distribution
• Semiexclusive production of vector mesons in proton-proton collisions with electromagnetic dissociation