Collectivity in Ultraperipheral Pb plus Pb Collisions at the Large Hadron Collider

We present the first full (3 + 1)D dynamical simulations of ultraperipheral Pb + Pb collisions at the Large Hadron Collider. Extrapolating from p + Pb collisions, we explore whether a quasireal photon gamma* interacting with the lead nucleus in an ultraperipheral collision can create a many-body system exhibiting fluid behavior. Assuming strong final-state interactions, we provide model results for charged hadron multiplicity, identified particle mean transverse momenta, and charged hadron anisotropic flow coef-ficients, and compare them with experimental data from the ALICE and ATLAS Collaborations. The elliptic flow hierarchy between p + Pb and gamma* + Pb collisions is dominated by the difference in longitudinal flow decorrelations and reproduces the experimental data well. We have demonstrated that our theoretical framework provides a quantitative tool to study particle production and collectivity for all system sizes, ranging from central heavy-ion collisions to small asymmetric collision systems at the Relativistic Heavy-Ion Collider and the Large Hadron Collider and even at the future Electron-Ion Collider.

Automated summary

The first full (3 + 1)D dynamical simulations of ultraperipheral Pb + Pb collisions at the Large Hadron Collider were presented to study particle production and collectivity, with results compared with experimental data, demonstrating the framework's quantitative tool for analyzing various system sizes.