We present measurements from events with two isolated prompt photons in p¯p collisions at √s =1.8 TeV. The differential cross section, measured as a function of transverse momentum (${\mathit{P}}_{\mathit{T}}$) of each photon, is about 3 times what next-to-leading-order QCD calculations predict. The cross section for photons with ${\mathit{P}}_{\mathit{T}}$ in the range 10–19 GeV is 86±27(stat${)}_{\mathrm{-}23}^{+32\mathrm{}}$(syst) pb. We also study the correlation between the two photons in both azimuthal angle and ${\mathit{P}}_{\mathit{T}}$. The magnitude of the vector sum of the transverse momenta of both photons, ${\mathit{K}}_{\mathit{T}}$=‖${\mathbf{P}}_{\mathit{T}1}$+${\mathbf{P}}_{\mathit{T}2}$‖, has a mean value of 〈${\mathit{K}}_{\mathit{T}}$〉=5.1±1.1 GeV.

• Received 23 December 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.2232