Isolated Photon Cross Section in the Central and Forward Rapidity Regions in p bar p Collisions at √s=1.8 TeV

A measurement of the cross section for production of single, isolated photons is reported for transverse energies in the range of 10 endash 125GeV for two regions of pseudorapidity, |η|<0.9 and 1.6<|η|<2.5. The data represent 12.9 pb-1 of integrated luminosity accumulated in bar pp collisions at √s=1.8 TeV and recorded with the D0 detector at the Fermilab Tevatron Collider. The background, predominantly from jets which fragment to neutral mesons, is estimated using the longitudinal shower shape in the calorimeter. In both pseudorapidity regions the cross section is found to agree with the next-to-leading order QCD prediction for 30 approx-lt ETγ approx-lt 80 GeV. copyright 1996 The American Physical Society