/ 93 07 35 5 v 1 2 8 Ju l 1 99 3 FSU – HEP – 930727 July 1993 RAPIDITY CORRELATIONS IN

We study the correlation of photon and charged lepton pseudorapidities, η(γ) and η(ℓ), ℓ = e, µ, in p¯ p → W ± γ + X → ℓ ± p / T γ + X at the Tevatron. In the Standard Model, the ∆η(γ, ℓ) = η(γ) − η(ℓ) differential cross section is found to exhibit a pronounced dip at ∆η(γ, ℓ) ≈ ∓0.4, which originates from the radiation zero present in q ¯ q ′ → W γ. The sensitivity of the ∆η(γ, ℓ) distribution to higher order QCD corrections, non-standard W W γ couplings, and the cuts imposed is explored. The ∆η(γ, ℓ) distribution is compared with other quantities which are sensitive to the radiation zero.