RAPIDITY CORRELATIONS IN W-GAMMA PRODUCTION AT HADRON COLLIDERS

We study the correlation of photon and charged lepton pseudorapidities , eta(gamma) and eta(l), l = e, mu, in ppBAR --> W+/-gamma + X --> l+/ -p(T)gamma + X. In the standard model, the DELTAeta(gamma, l) = eta(ga mma) - eta(l) differential cross section is found to exhibit a pronoun ced dip at DELTAeta(gamma, l) almost-equal-to -/+ 0.3 (= 0) in ppBAR ( pp) collisions, which originates from the radiation zero present in qq BAR' --> Wgamma. The sensitivity of the DELTAeta(gamma, l) distributio n to higher order QCD corrections, nonstandard WWgamma couplings, the W+ jet ''fake'' background, and the cuts imposed are explored. At hadr on supercolliders, next-to-leading order QCD corrections are found to considerably obscure the radiation zero. The advantages of the DELTAet a(gamma, l) distribution over. other quantities which are sensitive to the radiation zero are discussed. We conclude that photon-lepton rapi dity correlations at the Fermilab Tevatron offer a unique opportunity to search for the standard model radiation zero in hadronic Wgamma pro duction.