Seminar detail: Inclusive quarkonium photoproduction at the LHC via ultra-peripheral collisions

Date&Time	Tue Oct 03 2023 (17:00 - 18:00)
Speaker	Kate Lynch
Affiliation	IJCLab
Title	Inclusive quarkonium photoproduction at the LHC via ultra-peripheral collisions
Abstract	Quarkonia offer a unique laboratory to study the interplay between long- and short-distance hadronic physics. Despite being discovered almost 50 years ago, there is no single description of quarkonium production that can reproduce all of the data. In particular, no description can reconcile the hadro- and photoproduction data. Owing to the limited available photoproduction data, we explore the possibility to use ultra-peripheral proton-lead collisions at the LHC to study inclusive J/psi photoproduction, namely when a quasi-real photon emitted by the fully stripped lead ion breaks a proton to produce a J/psi. Owing to the extremely large energies of the colliding hadrons circulating in the LHC, the range of accessible energies largely exceed what has been and will be studied at lepton-hadron colliders like HERA and the LHC. We obtain a leading-order inclusive-photoproduction cross section of 50 microbarns, we find that inclusive-photoproduction can be isolated from possible hadroproduction processes by imposing the absence of significant activity in the lead-going direction, and may be further isolated by imposing rapidity-gap based cuts on detector activity. We estimate the background-to-signal ratio to be of order 0.001 and 0.01 at CMS and LHCb. In addition, we propose a method to reconstruct the collision energy of the photon-nucleon system as well as the elasticity, z. This reconstruction will allow kinematic regions to be defined that minimize theoretical uncertainty as well as offering a lever-arm to understand the quarkonium production mechanism. We find that z can be reconstructed with a resolution of 0.3 and 0.1 in the lowest and largest z regions, respectively.
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