Charmonia photo-production in ultra-peripheral and peripheral PbPb collisions with LHCb

TL;DR

This paper reports on precise measurements of photo-produced J/psi mesons in ultra-peripheral and peripheral PbPb collisions at the LHCb, revealing insights into collision geometry and electromagnetic fields with improved data quality.

Contribution

The study provides new measurements of charmonia photo-production in PbPb collisions with increased luminosity and detector resolution, enabling detailed analysis of collision geometry and electromagnetic effects.

Findings

Enhanced precision in J/psi photo-production measurements.

Insights into collision geometry and electromagnetic fields.

First detailed study in peripheral and ultra-peripheral collisions.

Abstract

The LHCb recorded $\sim$ 210 $\mu b^{-1}$ integrated luminosity of PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV in 2018. With an increase of the luminosity by a factor of 20 compared to the previous 2015 PbPb dataset, precise measurements on photo-produced charmonia in ultra-peripheral collisions are now possible. Moreover, the great momentum resolution of the detector allows photo-produced $J/\psi$ in collisions with a nuclear overlap to be studied. This new type of probe is sensitive to the geometry of the collisions but also to the electromagnetic field of the Pb nuclei. In this contribution, we present the latest results on $J/\psi$ photo-production measured by LHCb in peripheral and ultra-peripheral PbPb collisions.