Measurement of the exclusive $\gamma \gamma \to {\mu }^{+}{\mu }^{-}$ process in proton--proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The production of exclusive $\gamma \gamma \to {\mu }^{+}{\mu }^{-}$ events in proton–proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC, using data corresponding to an integrated luminosity of 3.2 fb${}^{-1}$. The measurement is performed for a dimuon invariant mass of 12 GeV $<m_{{\mu }^{+}{\mu }^{-}}<$ 70 GeV. The integrated cross-section is determined within a fiducial acceptance region of the ATLAS detector and differential cross-sections are measured as a function of the dimuon invariant mass. The results are compared to theoretical predictions that include corrections for absorptive effects.