# Geometry of ultraperipheral nuclear collisions

## TL;DR

This paper explores the geometric aspects of ultraperipheral heavy-ion collisions, emphasizing how the interaction region's shape influences electromagnetic and QCD processes, and evaluates related cross sections and resonance production possibilities.

## Contribution

It introduces a detailed analysis of the interaction geometry in ultraperipheral collisions and discusses potential new resonance production mechanisms under strong magnetic fields.

## Key findings

- Cross sections for electromagnetic resonance production are evaluated.
- Exclusive $
ho^0$-meson production via two-photon processes may occur in strong magnetic fields.
- The geometry significantly affects the relative importance of light-by-light scattering and QCD processes.

## Abstract

It is advocated that geometry of the interaction region of two heavy nuclei colliding at large impact parameters is important for the relative role of light-by-light scattering and QCD-initiated processes. Exclusive production of resonances is possible by dense electromagnetic fields in the interior space between the nuclei. The cross section of these processes is evaluated and some examples are considered. It is speculated that the exclusive production of $\rho ^0$-mesons by two-photon processes forbidden by the Landau-Yang rule may become allowed within strong magnetic fields.