Study of the inclusive $t\overline{t} + \gamma$ cross section with the CMS experiment

Photon radiation associated top quark pair production is investigated to quantify the electromagnetic coupling of quarks. The top-quark couplings are expected to be sensitive to effects of physics beyond the Standard Model. Generally, such effects can be spotted by probing top-correlated photon observables. We present a measurement of the inclusive cross section of the top-pair plus photon production, taking the course of a cumulative approach. Using a cut based event selection, we focus on top-pair events in the muon+jets channel with an additional high-energetic and well-isolated photon. The signal process ($pp \rightarrow q \bar q b \bar b \mu \nu_\mu \gamma$) is simulated with the LO event generator WHIZARD. A template-fit technique is applied to estimate the misidentification rate of photons in selected events.