engALICE CollaborationExclusive four pion photoproduction in ultraperipheral Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeVThe intense photon fluxes from relativistic nuclei provide an opportunity to study photonuclear interactions in ultraperipheral collisions. The measurement of coherently photoproduced \fourpi~final states in ultraperipheral $\rm{Pb\textendash Pb}$ collisions at \fivenn~is presented for the first time. The cross section, d$\sigma$/d$y$, times the branching ratio ($\rho\rightarrow \pi^+ \pi^+ \pi^- \pi^-$) is found to be $47.8\pm2.3~\rm{\rm{(stat.)}}\pm7.7~\rm{\rm{(syst.)}}$~mb in the rapidity interval $|y|doi:10.17182/HEPDATA.166318.V1info:eu-repo/semantics/researchdatainfo:eu-repo/semantics/publishedVersion2025info:eu-repo/semantics/closedAccessDEhttps://repository.gsi.de/record/363923https://repository.gsi.de/search?p=id:%22GSI-2026-00126%22Researchersinfo:eu-repo/semantics/altIdentifier/doi/10.17182/HEPDATA.166318.V1info:eu-repo/grantAgreement/EC//824093