Measurement of the associatedγ+μ±production cross section inpp¯collisions ats=1.8TeV

We present the first measurement of associated direct photon$+$muon production in hadronic collisions, from a sample of 1.8 TeV $p\overline{p}$ collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily from the Compton scattering process $c\stackrel{\ensuremath{\rightarrow}}{g}c\ensuremath{\gamma},$ with the final state charm quark producing a muon. Hence this measurement is sensitive to the charm quark content of the proton. The measured cross section of $29\ifmmode\pm\else\textpm\fi{}9$ pb is compared to a leading-order QCD parton shower model as well as a next-to-leading-order QCD calculation.