ISOLATED PHOTONS AT HADRON COLLIDERS AT O(ALPHA-ALPHA(S)(2)) .1. SPIN-AVERAGED CASE

The cross sections for isolated and non-isolated prompt photon product ion with unpolarized hadron beams are studied at order alpha alpha(s)( 2). Two methods of performing the calculations are compared, One uses purely analytic techniques and the second uses a combination of analyt ic and Monte Carlo techniques to perform the phase-space integrations. The results of the analytic and Monte Carlo methods are compared both before and after isolation cuts are placed on the photon. Fragmentati on contributions are included at next-to-leading order in the analytic case, and the question of the infrared sensitivity of this contributi on once isolation is implemented is addressed, Numerical results are p resented and compared with the latest CDF data for p (p) over bar --> gamma + X using the latest parton densities for the proton. (C) 1997 E lsevier Science B.V.