Dielectron production at low transverse momentum in Pb--Pb collisions at $ \sqrt{s_{\mathrm{NN}}}=5.02 $ TeV with ALICE

Dielectrons probe a wide range of phenomena in heavy-ion collisions. These include light- and heavy-flavour meson production, thermal radiation and coherent photo-production. The latter process is distinguished by dielectron production at low transverse-pair momentum ($ \it{p}_{\textrm{T,ee}}$). Transverse momentum spectra of dielectrons in central and peripheral Pb--Pb collisions are extracted and compared to the corresponding expectations. In central collisions the data fit the expected spectrum, which is dominated by semi-leptonic decays of correlated heavy-flavour hadrons. In peripheral collisions, the data exhibit an excess at low $ \it{p}_{\textrm{T,ee}}$ with respect to hadronic and thermal sources. The observed excess yield is compatible with calculations for dielectron production from coherent photon-photon interactions.