Importance of mesons in light-by-light scattering in ultraperipheral lead-lead collisions at the LHC

TL;DR

This paper explores the potential to measure light-by-light scattering and meson resonances in ultraperipheral lead-lead collisions at the LHC, highlighting the feasibility of observing specific meson peaks and reducing background noise.

Contribution

It provides new predictions for measuring photon-photon scattering and meson resonances at the LHC, including strategies for background reduction in ultraperipheral collisions.

Findings

Photon-photon collisions measurable for invariant mass > 2 GeV

Resonance scattering of η, η', and η_c mesons detectable with good statistics

Potential observation of meson-related peaks in ultraperipheral PbPb collisions

Abstract

Possibility of PbPb$\to$PbPb$\gamma\gamma$ measurement at smaller (< 5 GeV) diphoton invariant mass will be presented. Analysis focuses only on ultraperipheral heavy-ion collisions. This estimate shows that the $\gamma \gamma \to \gamma \gamma$ collisions can be measured at the LHC by ALICE and LHCb experiments for diphoton invariant mass $>$ 2 GeV. Predictions for the $\gamma\gamma \to \eta, \eta' \to \gamma\gamma$ resonance scattering shows that these resonances can be measured with rather good statistics. A~possible observation of peaks related to intermediate $\eta$, $\eta'(958)$, $\eta_c(1S)$, $\eta_c(2S)$, $\chi_{c0}(1P)$ mesons will be presented too. Attempts of reduction of background which comes from dipion production will be considered.