Light-by-light scattering cross-section measurements at LHC

TL;DR

This paper reviews light-by-light scattering cross-section measurements at the LHC, incorporating the $ ext{η}_b(1S)$ meson contribution, and finds results consistent with the Standard Model within uncertainties.

Contribution

It introduces the first calculation of the $ ext{η}_b(1S)$ meson contribution to diphoton production in light-by-light scattering at the LHC.

Findings

Measured cross-section: 115 ± 19 nb.

Results are consistent with Standard Model predictions.

Potential for ~10% improvement with more data.

Abstract

This note represents an attempt to gather the input related to light-by-light scattering ($\gamma\gamma$) cross-section measurements at LHC with the aim of checking the consistency with different standard model predictions. For the first time, we also consider the contribution from the $\eta_b(1S)$ meson production to the diphoton invariant mass distribution, by calculating its inclusive photoproduction cross-section. Using a simplified set of assumptions, we find a result of $115\pm 19\,\,\text{nb}$, consistent with standard model predictions within two standard deviations. Although an improved determination of the integrated fiducial $\textrm{PbPb}\,(\gamma\gamma)\to \textrm{Pb}^{(\ast)}\textrm{+}\textrm{Pb}^{(\ast)}\,\gamma\gamma$ cross-section by approximately 10\% could be potentially achieved relative to current measurements, further improvements are expected with the inclusion of existing or forthcoming LHC nuclear data.