Overview of J/psi Production in UPCs

Vector meson production in high-energy ultra peripheral collisions is an excellent tool to study the dynamics of small- x gluons inside nuclei. I will review calculations on exclusive and inclusive J/Psi and address their potential to elucidate nuclear effects including gluon saturation, as well as nuclear structure, sub-nucleonic fluctuations, and entanglement driven interference effects. I will focus on calculations within the Color Glass Condensate effective theory and briefly compare to other frameworks.