# XIV Hadron Physics 2018

18-23 March 2018
Florianopolis, Brazil
America/Sao_Paulo timezone

## Geometrical scaling description for the exclusive production of vector mesons and DVCS

19 Mar 2018, 16:00
1h
Florianopolis, Brazil

Poster

### Speaker

Felipe Gregoletto Ben (Universidade Federal do Rio Grande do Sul (UFRGS))

### Description

In this work, we investigate the exclusive production of particles in scattering processes in the so-called saturation region. Within this scheme the phenomenon of geometric scaling takes place: cross sections are functions only of a dimensionless combination of the relevant kinematic variables, which happens both in inclusive and diffractive cases, as in the production of vector mesons. In particular, the scaling variable is given in general by $\tau = Q^2/Q_s^2$, where $Q^2$ is the photon virtuality and $Q_s$ represents the saturation scale, which drives the energy dependence and the corresponding nuclear effects.
Based on the scaling property, we are able to derive a universal expression for the cross sections for the exclusive vector meson production and deeply virtual Compton scattering (DVCS) in both photon-proton and photon-nucleus interactions. This phenomenological result describes all available data from DESY-HERA for $\rho$, $\phi$ and $J/\psi$ production and DVCS measurements. A discussion is also carried out on the size of nuclear shadowing corrections on photon-nucleus interaction.

This work has been published in the following paper https://journals.aps.org/prd/abstract/10.1103/PhysRevD.96.054015

### Primary authors

Felipe Gregoletto Ben (Universidade Federal do Rio Grande do Sul (UFRGS)) Magno Machado (Universidade Federal do Rio Grande do Sul) Dr Werner Sauter (UFPel)