DPS mechanism for associated $c\bar{c} l^+l^-$ production in $AA$ UPCs as a probe for photon density inside the nucleus

TL;DR

This paper explores a novel method to probe the photon density inside nuclei by analyzing associated charm-anticharm and dilepton pair production in ultraperipheral heavy-ion collisions, focusing on double-parton scattering effects.

Contribution

It derives a new analog of the standard pocket formula for DPS in nuclear collisions and studies its kinematic dependence, including elastic and non-elastic contributions.

Findings

Predicted DPS $c\bar c l^+l^-$ production cross sections at LHC and future colliders.

Analyzed the dependence of the effective cross section on kinematic variables.

Provided differential cross section predictions for charm rapidity and dilepton invariant mass.

Abstract

We discuss the associated $c\bar{c}$ and $l^+l^-$ pairs production in ultraperipheral heavy-ion collisions at high energies. Such a channel provides a novel probe for double-parton scattering (DPS) at small $x$ enabling one to probe the photon density inside the nucleus. We have derived an analog of the standard central $pp$ pocket formula and studied the kinematical dependence of the effective cross section. Taking into account both elastic and non-elastic contributions, we have shown predictions for the DPS $c\bar c l^+l^-$ production cross section differential in charm quark rapidity and dilepton invariant mass and rapidity for LHC and a future collider.