Exchange-degenerate Regge trajectories: a fresh look from resonance and   forward scattering regions
  The exchange-degeneracy of the mesonic $f$, $\omega $, $\rho $ and $a_{2}$ Regge trajectories, dominant at moderate and high energies in hadron elastic scattering, is analyzed from two viewpoints. The first one concerns the masses of the resonances lying on these trajectories; the second one deals with the total cross-sections and the ratios of the real to the imaginary parts of the forward amplitudes of hadron and photon induced reactions. Neither set of data supports exact exchange-degeneracy. 
P.Desgrolard, M.Giffon, E.Martynov, E.Predazzi