MEASURING THE WW-GAMMA VERTEX IN THE PROCESS EP-]GAMMA-NU-X

We present a detailed analysis of the process ep --> gamma-nu-X as a means of studying the gauge structure of the WW-gamma vertex. We find that the differential cross section of high p(T) photons offers a sensitive measure of anomalous WW-gamma couplings. At HERA (square-root s = 314 GeV), after several years of running, the WW-gamma vertex can be measured to delta-kappa(gamma) congruent-to +2.9/-2.0 and delta-lambda(gamma) congruent-to +3.0/-2.5 (95% C.L.) which offers an improvement over existing constraints from direct measurements using associated W-gamma production in ppBAR collisions but is less sensitive than the competing process at HERA, ep --> eWX. For a higher energy ep collider, LEP-LHC (square-root s = 1.3 TeV), the WW-gamma vertex can be measured to delta-kappa(gamma) congruent-to +/-0.4 and delta-lambda(gamma) congruent-to +/-0.1 at 95% C.L. which is more sensitive to lambda(gamma) than the process e+e- --> W+W- at the LEP200 e+e- collider and is comparable to the LEP200 sensitivity to kappa(gamma). These values are also roughly comparable to the competing process ep --> eWX at LEP-LHC and to what is expected from associated gamma-W production at the LHC and SSC for kappa(gamma) but they are about half as sensitive to lambda(gamma) as the LHC and SSC.