Speaker
Description
Photon-induced vector meson production in ultraperipheral heavy-ion collisions (UPCs) offers a unique and powerful probe of the gluon distribution in nuclei. Coherent vector meson photoproduction in UPCs of lighter species such as the $\rho0$ and $\phi$ serves as a powerful tool for investigating the gluon structure of nuclei at small Bjorken-$x$, accessing lower energy scales with potential sensitivity to gluon saturation and nuclear shadowing. We will present the differential cross sections for coherent $\phi$ meson and coherent $\rho^0$ meson photoproduction in Pb+Pb UPCs at $\sqrt{s_{NN}} = 5.36$ TeV with the CMS detector. Additionally the coherent $\rho^0$ photoproduction crosssection is measured as a function of photon-nucleus center-of-mass energies per nucleon ($W_{\gamma A}$) over a wide range of $26 < W < 158$ GeV. The results are compared with model predictions, with observed differences providing potential insight into the underlying production dynamics.