RATIOS OF W-PLUS-OR-MINUS-GAMMA AND Z-GAMMA CROSS-SECTIONS - NEW TOOLS IN PROBING THE WEAK BOSON SECTOR AT THE FERMILAB TEVATRON

The ratios R(gamma,l) = B(Z --> l+l-)sigma(Zgamma)/B (W --> lnu)sigma( W+/-gamma), R(gamma,nu) = B(Z --> nunuBAR)sigma(Zgamma)/B(W --> lnu)si gma(W+/-gamma), R(Wgamma) = sigma(W+/-gamma)/sigma(W+/-), and R(Zgamma ) = sigma(Zgamma)/sigma(Z) are studied as tools to probe the electrowe ak boson self-interactions. As a function of the minimum photon transv erse momentum, R(gamma,l) and R(gamma,nu) are found to directly reflec t the radiation zero present in W+/-gamma production in the standard m odel. All four ratios are sensitive to anomalous WWgamma and/or ZZgamm a/Zgammagamma couplings. The sensitivity of the cross-section ratios t o the cuts imposed on the final-state particles, as well as the system atic uncertainties resulting from different parametrizations of parton distribution functions, the choice of the factorization scale Q2, and from higher-order QCD corrections, are explored. Taking into account these uncertainties, sensitivity limits for anomalous three gauge boso n couplings, based on a measurement of the cross-section ratios with a n integrated luminosity of 25 pb-1 at the Fermilab Tevatron, are estim ated.