Exclusive production of vector mesons in $\gamma p$ and $p p$ collisions

TL;DR

This paper investigates the exclusive production of vector mesons in gamma-proton and proton-proton collisions using pQCD, providing theoretical predictions and comparisons with experimental data for various mesons at different energies.

Contribution

It presents a pQCD $k_{T}$-factorization calculation of photoproduction amplitudes for multiple vector mesons, including energy dependence and model comparisons, for the first time in this context.

Findings

Calculated cross sections for vector meson production as functions of energy and photon virtuality.

Compared theoretical results with HERA data for validation.

Provided predictions for rapidity, transverse momentum, and azimuthal distributions at Tevatron and LHC energies.

Abstract

The dominant mechanism for the central exclusive production of vector meson in $p p$ and $p \bar p$ collisions is the $\gamma$ $I P$ fusion. As a building block for the pp reaction, the amplitude for photoproduction $ \gamma p \to V p $ is calculated in a pQCD $k_{T}$- factorization approach. We will present results for several vector mesons: $\rho$, $\omega$, $\phi$, $J/\Psi$ and $\Upsilon$. The total cross section for diffractive mesons production as a function of energy and photon virtuality is calculated. We will present dependence on the mass of the quark for light mesons. The results for $ \gamma p \to V p $ photoproduction depend on the model of the meson wave function. We compare our results with a HERA data for photon-proton collisions. Finally we turn to pp collisions, and we present distribution in rapidity, transverse momentum of vector mesons and azimuthal angle between outgoing protons for Tevatron and LHC energies. The absorption effects will be discussed.