Bjoern Penning (University of Chicago (US))
We present measurements of the differential cross section dsigma/dpT_gamma for the inclusive production of a photon in association with a b/c-quark jet. The results are based on data corresponding to an integrated luminosity of 8.7 fb^-1, recorded with the D0 detector at the Fermilab Tevatron ppbar collider at sqrt(s)=1.96 TeV. The measured cross sections are compared with next-to-leading order perturbative QCD calculations using different sets of parton distribution functions as well as to predictions based on the kT-factorization QCD approach, and those from the Sherpa and Pythia Monte Carlo event generators. We also present measurements of the direct photon pair production cross sections using 8.5 fb^-1 of data collected with the D0 detector. The results are shown as differential distributions with respect to the photon pair mass, pair transverse momentum, azimuthal angle, and polar scattering angle in the Collins-Soper frame. Measurements are performed for the photon transverse momenta pT > 17 and 18 GeV with rapidities |y|<0.9. The results are compared with the predictions from NNLO, NLO QCD and Monte Carlo event generators.
The DØ Collaboration (Fermi National Laboratory)