Photoproduction of J/ψ and dileptons in Pb–Pb collisions with nuclear overlap
Year: 2025
Type: conference-paper
Abstract: Photon-photon reactions and the production of J/ψ meson through photonuclear reactions have been extensively studied in ultra-peripheral heavy-ion collisions, in which the impact parameter is larger than twice the nuclear radius. In recent years, coherently photoproduced J/ψ and dilepton production via photon-photon interactions have also been observed in nucleus-nucleus (A–A) collisions with nuclear overlap. The former can help to constrain the nuclear gluon distributions at low Bjorken-x and high energy, while the latter could be used to further map the electromagnetic fields produced in heavy-ion collisions. In addition, these measurements can shed light on the theory behind photon-induced reactions in A–A collisions with nuclear overlap, including possible interactions of the measured probes with the formed and fast expanding quark-gluon plasma. Since the produced quarkonium is expected to keep the polarization of the incoming photon due to s-channel helicity conservation, the photoproduction origin of the J/ψ yield excess at very low transverse momentum, pT, can be confirmed by the measurement of the J/ψ polarization. The ALICE detector can perform quarkonium production measurements at both mid (|y|<0.9) and forward (2.5
DOI: 10.17161/8vtpsj90
Author: N. Biz´e
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4408326408