Isolated prompt singlephoton and diphoton production in {ovr p}p collisions

A measurement of the differential cross section d{sup 2}{sigma}/dE{sub T}d{eta} of isolated prompt photons, {ovr p}p {r_arrow} {gamma} + X is presented for two pseudorapidity ranges, |{eta}| < 0.9 and 1.6 < |{eta}| < 2.5, at {radical}s = 1.8 TeV. The data were accumulated during the 1992-1993 tevatron collider run (1A), consisting of 13 pb{sup -1} of integrated luminosity. The background is estimated by measuring the longitudinal shower profile in the four layers of the electromagnetic (EM) calorimeter. The results show good agreement with the next-to-leading-order QCD (NLO) calculations in the range 30 {approx_lt} E{sub T} {approx_lt} 80 GeV. A preliminary measurement of isolated prompt diphoton production, {ovr p}p {r_arrow} {gamma}{gamma} + X is also presented for the pseudorapidity range |{eta}| < 1.0. The data sample corresponds to an integrated luminosity of 80.0 pb{sup -1} from the 1994-1995 run (1B). Preliminary cross section measurements of d{sigma}/dE{sub T}, d{sigma}/dM and (1/{sigma})d{sigma}/dK{sub T} are reported and compared to the Pythia Monte Carlo. The K{sub T} (defined as K{sub T} = |{rvec P}{sup 1}{sub T} + {rvec P}{sup 2}{sub T}|) of the two photon system is measured in the range 0 < K{sub T} < 22 GeV. The shape at low K{sub T} data favors NLO QCD with an intrinsic = 2 GeV rather than the Pythia Monte Carlo or the NLO QCD calculation without an intrinsic . 9 refs., 6 figs., 1 tab