Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2504.07795 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866910908424388608 |
|---|---|
| author | ATLAS Collaboration |
| author_facet | ATLAS Collaboration |
| contents | The Lorentz-contracted electromagnetic fields of the ions in ultra-relativistic heavy-ion collisions generate intense quasi-real photon fluxes. These lead to photon-induced interactions that are observed in ultra-peripheral collisions (UPCs), such as vector meson and lepton-pair production. The high photon flux also enables the occurrence of multiple photon-induced processes in a single collision. Presented is the first measurement of the coincident production of $γγ\rightarrow μ^{+}μ^{-}$ and $γ+A\rightarrowρ^{0}+A$ in UPC Pb+Pb collisions at centre-of-mass energies of 5.02 TeV and 5.36 TeV with the ATLAS detector at the Large Hadron Collider. The rate of the coincident process relative to the exclusive $γγ\rightarrow μ^{+}μ^{-}$ process is measured differentially in intervals of forward event activity, quantified by the Zero Degree Calorimeters. The relative rate, summed over forward event activity, for the coincident $ρ^{0}$ production is measured to be $(9.3\,\pm0.4\,\mathrm{(stat.)}\,\pm0.2\,\mathrm{(syst.)})\times10^{-3}$. Correlations between the dimuon kinematic properties, such as its mass, and the coincident $ρ^{0}$ meson production rate, are also presented. These measurements confirm the presence of multi photon-induced processes in UPC collisions, and can provide new insight into the impact parameter dependence of photon-induced vector meson production. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2504_07795 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Measurement of coincident photon-initiated processes in ultra-peripheral Pb+Pb collisions with the ATLAS detector ATLAS Collaboration Nuclear Experiment High Energy Physics - Experiment The Lorentz-contracted electromagnetic fields of the ions in ultra-relativistic heavy-ion collisions generate intense quasi-real photon fluxes. These lead to photon-induced interactions that are observed in ultra-peripheral collisions (UPCs), such as vector meson and lepton-pair production. The high photon flux also enables the occurrence of multiple photon-induced processes in a single collision. Presented is the first measurement of the coincident production of $γγ\rightarrow μ^{+}μ^{-}$ and $γ+A\rightarrowρ^{0}+A$ in UPC Pb+Pb collisions at centre-of-mass energies of 5.02 TeV and 5.36 TeV with the ATLAS detector at the Large Hadron Collider. The rate of the coincident process relative to the exclusive $γγ\rightarrow μ^{+}μ^{-}$ process is measured differentially in intervals of forward event activity, quantified by the Zero Degree Calorimeters. The relative rate, summed over forward event activity, for the coincident $ρ^{0}$ production is measured to be $(9.3\,\pm0.4\,\mathrm{(stat.)}\,\pm0.2\,\mathrm{(syst.)})\times10^{-3}$. Correlations between the dimuon kinematic properties, such as its mass, and the coincident $ρ^{0}$ meson production rate, are also presented. These measurements confirm the presence of multi photon-induced processes in UPC collisions, and can provide new insight into the impact parameter dependence of photon-induced vector meson production. |
| title | Measurement of coincident photon-initiated processes in ultra-peripheral Pb+Pb collisions with the ATLAS detector |
| topic | Nuclear Experiment High Energy Physics - Experiment |
| url | https://arxiv.org/abs/2504.07795 |