Quarkonia production in ultra-peripheral PbPb collisions at LHCb

TL;DR

This paper reports precise measurements of coherent charmonium production in ultra-peripheral PbPb collisions at the LHCb, confirming theoretical models and enhancing understanding of quarkonium production mechanisms.

Contribution

It provides new differential cross-section measurements of si mesons as functions of rapidity and transverse momentum, improving upon previous data and confirming coherent production in hadronic collisions.

Findings

Measured differential cross-sections as functions of rapidity and transverse momentum.

Confirmed coherent si production in hadronic collisions.

Results agree with some theoretical predictions.

Abstract

Measurements of coherent charmonium production cross sections together with their ratio in ultra-peripheral PbPb collisions are studied at a nucleon-nucleon centre-of-mass energy of $5.02\,\mathrm{TeV}$, the differential cross-sections are measured as a function of rapidity and transverse momentum, separately. The photo-production of \jpsi mesons at low transverse momentum is studied in peripheral PbPb collisions, which confirms coherent \jpsi production in hadronic collisions. These latest results significantly improve previous measurements and are compared with some theoretical predictions.