Energy Dependence of Polarized $\mathbf{\gamma\gamma\rightarrow e^{+}e^{-}}$ in Peripheral Au+Au Collisions at RHIC
Nuclear Experiment
2024-07-23 v1 High Energy Physics - Experiment
Abstract
We report the differential yields at mid-rapidity of the Breit-Wheeler process () in peripheral Au+Au collisions at 54.4 GeV and 200 GeV with the STAR experiment at RHIC, as a function of energy , transverse momentum , , invariant mass and azimuthal angle. In the invariant mass range of 0.4 2.6 GeV/ at low transverse momentum ( 0.15 GeV/), the yields increase while the pair decreases with increasing , a feature is correctly predicted by the QED calculation. The energy dependencies of the measured quantities are sensitive to the nuclear form factor, infrared divergence and photon polarization. The data are compiled and used to extract the charge radius of the Au nucleus.
Keywords
Cite
@article{arxiv.2407.14821,
title = {Energy Dependence of Polarized $\mathbf{\gamma\gamma\rightarrow e^{+}e^{-}}$ in Peripheral Au+Au Collisions at RHIC},
author = {The STAR Collaboration},
journal= {arXiv preprint arXiv:2407.14821},
year = {2024}
}