Cross section and heavy quark composition ofγ+μevents produced inpp¯collisions

We present a measurement of the cross section and the first measurement of the heavy flavor content of associated direct photon + muon events produced in hadronic collisions. These measurements come from a sample of $1.8\hspace{0.5em}\mathrm{TeV}$ $p\overline{p}$ collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily due to the Compton scattering process $c\overrightarrow{g}c\gamma ,$ with the final-state charm quark producing a muon. The cross section for events with a photon transverse momentum between 12 and $40\hspace{0.5em}\mathrm{GeV}/c$ is measured to be $46.8\pm 6.3\pm 7.5\hspace{0.5em}\mathrm{pb},$ which is two standard deviations below the most recent theoretical calculation. A significant fraction of the events in the sample contain a final-state bottom quark. The ratio of charm to bottom production is measured to be $2.4\pm 1.2,$ in good agreement with QCD models.