Production of $\eta_b$ in ultra-peripheral $Pb Pb$ collisions

TL;DR

This paper calculates the production cross section of the $ ext{η}_b$ meson in ultra-peripheral lead-lead collisions using recent lattice QCD results for its decay width, providing a novel application in heavy ion physics.

Contribution

First application of lattice QCD decay width results to compute $ ext{η}_b$ production in ultra-peripheral collisions, with a comprehensive analysis of collision definitions and photon flux treatments.

Findings

Calculated $ ext{η}_b$ production cross section in UPCs.

Analyzed different definitions of ultra-peripheral collisions.

Compared various methods of photon flux treatment.

Abstract

Very recently, the two-photon decay width of the $\eta_b$ meson was computed with lattice QCD methods. This decay has not yet been measured. The knowledge of this width allows for the calculation of the $\eta_b$ production cross section through photon-photon interactions in ultra-peripheral $PbPb$ collisions. In this work we present this calculation, which is the first application of the lattice result. Since UPCs are gaining an increasing attention of the heavy ion community, we take the opportunity to perform a comprehensive study of the different ways of defining ultra-peripheral collisions and of the different ways to treat the equivalent photon flux.