Evidence for electroweak production of two jets in association with a Pair in Collisions at with the ATLAS detector

Evidence for electroweak production of two jets in association with a Zγ pair in $\sqrt{s}=13\text{TeV}$ proton–proton collisions at the Large Hadron Collider is presented. The analysis uses data collected by the ATLAS detector in 2015 and 2016 that corresponds to an integrated luminosity of $36.1\phantom{\rule{0.25em}{0ex}}{\mathrm{fb}}^{-1}$. Events that contain a Z boson candidate decaying leptonically into either ${e}^{+}{e}^{-}$ or ${\mu }^{+}{\mu }^{-}$, a photon, and two jets are selected. The electroweak component is measured with observed and expected significances of 4.1 standard deviations. The fiducial cross-section for electroweak production is measured to be ${\sigma }_{Z\gamma jj-\mathrm{EW}}=7.8\phantom{\rule{0.25em}{0ex}}±2.0\phantom{\rule{0.25em}{0ex}}\mathrm{fb}$, in good agreement with the Standard Model prediction.