Photoproduction of Upsilon states in ultraperipheral collisions at the LHC

Magno Machado,A Ayala Mercado,E Cuautle Flores

doi:10.1051/epjconf/201817206001

Abstract

The exclusive photoproduction of upsilon states is investigated in the context of ultra-peripheral collisions at the LHC energies. Predictions are presented for their production in proton-proton, proton-nucleus and nucleus-nucleus collisions at the energies available at the LHC run 2. The theoretical framework considered in the analysis is the light-cone color dipole formalism, which includes consistently parton saturation effects and nuclear shadowing corrections. For PbPb collisions we consider both the coherent and incoherent contributions.

Highlights

The exclusive photoproduction of heavy vector mesons is a kind of diffractive process where, besides a soft scale characterized by the hadron size, there is clearly a hard scale that allows to analyse the reaction from the perturbative QCD point of view
The absorption corrections in this case is not strong as in the corresponding final state in proton-proton collisions. In this contribution we summarize the results obtained in Refs. [6, 7], where we investigate the exclusive production of Υ(1S ) and its radially excited states Υ(2S ) and Υ(3S ) in PbPb collisions for LHC energy
We presented the predictions of rapidity distribution and integrated cross sections for the Υ(1S, 2S, 3S ) states for the LHC energies, including discussions for pp and pA modes and fosusing mainly on PbPb collisions

Summary

Introduction

The exclusive photoproduction of heavy vector mesons is a kind of diffractive process where, besides a soft scale characterized by the hadron size, there is clearly a hard scale (mesons mass mV ) that allows to analyse the reaction from the perturbative QCD point of view. The rapidity gap describes a region between the axis beam and the decay of meson (e+ + e−, μ− + μ+) free of particles In this way, the experimental observation of this kind of quasi-diffractive process is facilitated. The absorption corrections in this case is not strong as in the corresponding final state in proton-proton collisions In this contribution we summarize the results obtained in Refs. PbPb collisions at the LHC has been considered Those calculations were carried out in the theoretical framework of the color light-cone dipole formalism [2] and focused only on the coherent channel where the initial state particles remain intact after interaction.

Theoretical Framework

Results and discussions

Summary