Relations between Reggeon and photon couplings

Abstract

We propose (a) "the vector coupling hypothesis" (VCH) that the leading normal parity regge trajectories (P, f, w, p, A(_2)) couple to quarks like vector particles, and (b) the "gamma analogy hypothesis" (GAH) that the couplings of P, f and w to any quark are proportional to the isoscalar photon coupling while the P and A(_2) couple like the isovector photon. These hypotheses are motivated by duality and vector dominance. Within the context of a naive ideally-mixed quark model we specify the spin-dependent nature of our coupling relations using the technique of covariant reggeization. As a major test of our hypotheses we use the formalism to elucidate the nature of the elastic scattering amplitudes and hence describe All the data on elastic scattering. We also make successful predictions for vector meson-proton cross-sections. Using these elastic scattering amplitudes we extend the formalism to predict (up to one free parameter) diffractive boson and baryon differential cross- sections. We find that our hypotheses successfully describe both the energy and t-dependence of all these cross-sections despite the fact that the helicity structure is much richer than, and the t-dependence quite different from, elastic scattering. We also use the meson couplings determined in our fits to predict the mesonic decay widths of resonances lying on the exchanged trajectories. Good agreement with experiment is found.