Inclusive spectra of isolated di-photon candidates using 6.4 pb$^{−1}$ of $pp$ collisions at $\sqrt{s}$ = 13 TeV

We present the inclusive $m_{\gamma\gamma}$, $p_{{\rm T}, \gamma\gamma}$ and $\Delta\phi_{\gamma\gamma}$ spectra of isolated di-photon pairs passing a tight selection criterion in 6.4 pb$^{-1}$ of $pp$ collision data collected by ATLAS at $\sqrt{s}= 13$ TeV in 2015. Di-photon candidates are formed from photon candidates with transverse momentum larger then 15 GeV, selected in the precision acceptance of the ATLAS electromagnetic calorimeter ($|\eta|< 1.37$ and $1.52 <|\eta| < 2.37$), and having an angular separation $\Delta R_{\gamma\gamma} > 0.4$. The isolation properties of the selected photon candidates are discussed, in comparison to those of background-enriched samples.