Konstantinos Vellidis (Fermilab)
We report measurements of the direct photon pair production cross section in ppbar collisions at the Fermilab Tevatron Collider using data collected by the CDF and D0 experiments and corresponding to integrated luminosities of 5.3 and 4.2/fb, respectively. Differential cross section measurements are compared with different perturbative QCD predictions, indicating significant disagreements between data and theory in regions of the phase space, suggesting the need for further theoretical studies of the di-photon production process. We also report measurement of the inclusive direct photon production cross section using data from the CDF experiment corresponding to an integrated luminosity of 2.5/fb and measurements of the gamma+b+X and gamma+c+X differential cross sections using data from the D0 experiment corresponding to an integrated luminosity of 1/fb. Results are compared to next-to-leading order perturbative QCD predictions.