Searching for axionlike particles with low masses in $pPb$ and $PbPb$ collisions

TL;DR

This paper investigates the potential to detect axionlike particles with low masses in ultraperipheral proton-lead and lead-lead collisions at the LHC, focusing on diphoton final states and the sensitivity of future experiments.

Contribution

It provides a detailed analysis of ALP production and background estimation in ultraperipheral collisions, proposing that LHCb can improve existing limits on ALP-photon coupling in the 2-5 GeV mass range.

Findings

Future LHCb measurements can enhance ALP exclusion limits.

Diphoton production analysis is feasible with realistic kinematic cuts.

Sensitivity to ALPs in the 2-5 GeV mass range is promising.

Abstract

The production of axionlike particles (ALPs) with small masses in ultraperipheral $Pb - p$ and $Pb - Pb$ collisions at the LHC is investigated. The cross section and kinematical distributions associated to the diphoton final state produced in the $\gamma \gamma \rightarrow a \rightarrow \gamma \gamma$ subprocesses are estimated considering a realistic set of kinematical cuts. A detailed analysis of the backgrounds is performed and the expected sensitivity to the ALP production is derived. Our results demonstrate that a future experimental analysis of the exclusive diphoton production for the forward rapidities probed by the LHCb detector can improve the existing exclusion limits on the ALP - photon coupling in the mass range 2 GeV $\le m_a \le$ 5 GeV.