Exclusive production of $\pi^+\pi^-$ and $\pi^0\pi^0$ pairs in photon-photon and in ultrarelativistic heavy ion collisions

TL;DR

This paper models the production of pion pairs in photon-photon and ultrarelativistic heavy ion collisions, incorporating various physical mechanisms to predict cross sections relevant for experiments like those at the LHC.

Contribution

It provides a comprehensive theoretical framework including multiple mechanisms for pion pair production in photon-photon and heavy ion collisions, with specific predictions for LHC energies.

Findings

Predicted cross sections for pion pair production at LHC energies

Inclusion of resonances, rescatterings, and pQCD mechanisms in the model

Predictions applicable for experimental measurement by ALICE

Abstract

The $\gamma\gamma\to\pi\pi$ reactions are discussed. To describe those processes, we include dipion continuum, resonances, high-energy pion-pion rescatterings, $\rho$ meson exchange and pQCD Brodsky-Lepage mechanisms. The cross section for the production of pion pairs in photon-photon collisions in peripheral heavy ion collisions is calculated with the help of Equivalent Photon Approximaption (EPA) in the impact parameter space. We show predictions at $\sqrt{s_{NN}}=3.5$ TeV which could be measured e.g. by the ALICE collaboration at the LHC.