Measurement of the differential cross section for the production of an isolated photon with associated jet in pp‾ collisions at √s=1.9 TeV

Abstract

The process pp→ y+jet+X is studied using 1.0 fb^-1 of data collected by the D0 detector at the Fermilab Tevatron pp‾ collider at a center-of-mass energy √ s=1.96 TeV . Photons are reconstructed in the central rapidity region |γγ|<1.0 with transverse momenta in the range 30 <P_T^γ<400 GeV while jets are reconstructed in either the central |γjet|<0.8 or forward 1.5<|γjet|<2.5 rapidity intervals with P_T^jet> 15 GeV. The differential cross section d³σ/dP_T^γ dy^γ dy^jet is measured as a function of P_T^γ in four regions, differing by the relative orientations of the photon and the jet in rapidity. Ratios between the differential cross sections in each region are also presented. Next-to-leading order QCD predictions using different parameterizations of parton distribution functions and theoretical scale choices are compared to the data. The predictions do not simultaneously describe the measured normalization and P_T^γ dependence of the cross section in the four measured regions.