Measurement of the Inclusive Top-Quark Pair + Photon Production Cross Section

The production cross section of top-quark pairs associated with a photon ($t\bar t+\gamma$) is determined in the muon+jets decay channel using 19.7 fb-1 of data taken at $\sqrt{s} = 8$ TeV with the CMS detector. The relative fraction of $t\bar t+\gamma$ events normalized to inclusive $t\bar t$ production is measured. Using an inclusive CMS cross section measurement, the $t\bar t+\gamma$ cross section is determined and found to agree with the Standard Model expectation.