# Nuclear Physics Seminar

## "The cos 2φ azimuthal asymmetry in ρ^0 meson production in ultraperipheral heavy ion collisions."

#### Presented by Jian Zhou, Shandong University

Tuesday, July 14, 2020, 11:00 am — Webcast

We present a detailed study of vector meson photoproduction in ultraperipheral heavy ion collisions (UPCs). Using the dipole model, we develop a framework for the joint impact parameter and transverse momentum dependent cross sections. We compute the unpolarized cross section and cos 2φ azimuthal angular correlation for ρ^0 photoproduction with φ defined as the angle between the ρ^0 's transverse spin vector and its transverse momentum. Our result on unpolarized coherent differential cross section gives excellent description to the STAR experimental data. A first comparison between theoretical calculation and experimental measurement on the cos 2φ azimuthal asymmetry, which results from the linearly polarized photons, is performed and reasonable agreement is reached. We find out the characteristic diffractive patterns at both RHIC and LHC energies and predict the impact parameter dependent cos 2φ azimuthal asymmetries for ρ^0 photoproduction by considering UPCs and peripheral collisions.

Hosted by: Rongrong Ma

15818 | INT/EXT | Events Calendar