$V'Z$ and $V'W$ Production as Tests of Heavy Gauge Boson Couplings at Future Hadron Colliders

Abstract

We point out that the production cross section of $pp\to V'V$, with $V'=W',Z'$ and $V=W,Z$ is a useful diagnostic of $V'$ gauge couplings at future hadron colliders. For $M_{Z'}\simeq1$ TeV it would allow determination of combinations of $Z'$ gauge couplings to the quarks to around 10 percent. An analysis of the extraction of gauge couplings from the complementary tests: forward-backward asymmetry, rare decays $pp\to V'\to f_1{\bar f_2}V$, and the production cross section $pp\to V'V$ is given in a model-independent framework. Four ratios of charges are needed to characterize a general gauge theory with an additional family-independent $U_1'$ factor. We show that there are four functions of these ratios observable at hadron colliders, but for projected SSC and LHC luminosities only two combinations can be extracted. These yield a significant discrimination between interesting GUT-motivated models. Clean tests of whether a new $W'$ couples to right-handed currents, of the ratio $g_R/g_L$ of gauge couplings, and of the non-abelian vertex in left-right symmetric models are described.